The utility of animal behavior studies in natural resource management

USDA-ARS?s Scientific Manuscript database

Although research on the behavior of individual animals has been growing in recent years in parts of the scientific community, the role that individual variation among animals may play in the outcome of species interactions in nature may be somewhat overlooked in natural resource management. Recogni...

Animal clocks: when science meets nature.

PubMed

Kronfeld-Schor, Noga; Bloch, Guy; Schwartz, William J

2013-08-22

Daily rhythms of physiology and behaviour are governed by an endogenous timekeeping mechanism (a circadian 'clock'), with the alternation of environmental light and darkness synchronizing (entraining) these rhythms to the natural day-night cycle. Our knowledge of the circadian system of animals at the molecular, cellular, tissue and organismal levels is remarkable, and we are beginning to understand how each of these levels contributes to the emergent properties and increased complexity of the system as a whole. For the most part, these analyses have been carried out using model organisms in standard laboratory housing, but to begin to understand the adaptive significance of the clock, we must expand our scope to study diverse animal species from different taxonomic groups, showing diverse activity patterns, in their natural environments. The seven papers in this Special Feature of Proceedings of the Royal Society B take on this challenge, reviewing the influences of moonlight, latitudinal clines, evolutionary history, social interactions, specialized temporal niches, annual variation and recently appreciated post-transcriptional molecular mechanisms. The papers emphasize that the complexity and diversity of the natural world represent a powerful experimental resource.

Animal Rights: Selected Resources and Suggestions for Further Study.

ERIC Educational Resources Information Center

Davidoff, Donald J.

1989-01-01

Presents an annotated list of selected resources intended to serve as a guide to the growing amount of material on animal rights. Suggestions to aid in additional research include subject headings used to find books, indexes used to locate periodical articles, sources for locating organizations, and a selected list of animal rights organizations.…

Natural selection promotes antigenic evolvability.

PubMed

Graves, Christopher J; Ros, Vera I D; Stevenson, Brian; Sniegowski, Paul D; Brisson, Dustin

2013-01-01

The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed 'cassettes' that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections.

Natural Selection Promotes Antigenic Evolvability

PubMed Central

Graves, Christopher J.; Ros, Vera I. D.; Stevenson, Brian; Sniegowski, Paul D.; Brisson, Dustin

2013-01-01

The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed ‘cassettes’ that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections

Natural Selection in the Great Apes

PubMed Central

Cagan, Alexander; Theunert, Christoph; Laayouni, Hafid; Santpere, Gabriel; Pybus, Marc; Casals, Ferran; Prüfer, Kay; Navarro, Arcadi; Marques-Bonet, Tomas; Bertranpetit, Jaume; Andrés, Aida M.

2016-01-01

Natural selection is crucial for the adaptation of populations to their environments. Here, we present the first global study of natural selection in the Hominidae (humans and great apes) based on genome-wide information from population samples representing all extant species (including most subspecies). Combining several neutrality tests we create a multi-species map of signatures of natural selection covering all major types of natural selection. We find that the estimated efficiency of both purifying and positive selection varies between species and is significantly correlated with their long-term effective population size. Thus, even the modest differences in population size among the closely related Hominidae lineages have resulted in differences in their ability to remove deleterious alleles and to adapt to changing environments. Most signatures of balancing and positive selection are species-specific, with signatures of balancing selection more often being shared among species. We also identify loci with evidence of positive selection across several lineages. Notably, we detect signatures of positive selection in several genes related to brain function, anatomy, diet and immune processes. Our results contribute to a better understanding of human evolution by putting the evidence of natural selection in humans within its larger evolutionary context. The global map of natural selection in our closest living relatives is available as an interactive browser at http://tinyurl.com/nf8qmzh. PMID:27795229

A Conceptual Characterization of Online Videos Explaining Natural Selection

NASA Astrophysics Data System (ADS)

Bohlin, Gustav; Göransson, Andreas; Höst, Gunnar E.; Tibell, Lena A. E.

2017-11-01

Educational videos on the Internet comprise a vast and highly diverse source of information. Online search engines facilitate access to numerous videos claiming to explain natural selection, but little is known about the degree to which the video content match key evolutionary content identified as important in evolution education research. In this study, we therefore analyzed the content of 60 videos accessed through the Internet, using a criteria catalog with 38 operationalized variables derived from research literature. The variables were sorted into four categories: (a) key concepts (e.g. limited resources and inherited variation), (b) threshold concepts (abstract concepts with a transforming and integrative function), (c) misconceptions (e.g. that evolution is driven by need), and (d) organismal context (e.g. animal or plant). The results indicate that some concepts are frequently communicated, and certain taxa are commonly used to illustrate concepts, while others are seldom included. In addition, evolutionary phenomena at small temporal and spatial scales, such as subcellular processes, are rarely covered. Rather, the focus is on population-level events over time scales spanning years or longer. This is consistent with an observed lack of explanations regarding how randomly occurring mutations provide the basis for variation (and thus natural selection). The findings imply, among other things, that some components of natural selection warrant far more attention in biology teaching and science education research.

Sexual selection predicts species richness across the animal kingdom.

PubMed

Janicke, Tim; Ritchie, Michael G; Morrow, Edward H; Marie-Orleach, Lucas

2018-05-16

Our improving knowledge of the animal tree of life consistently demonstrates that some taxa diversify more rapidly than others, but what contributes to this variation remains poorly understood. An influential hypothesis proposes that selection arising from competition for mating partners plays a key role in promoting speciation. However, empirical evidence showing a link between proxies of this sexual selection and species richness is equivocal. Here, we collected standardized metrics of sexual selection for a broad range of animal taxa, and found that taxonomic families characterized by stronger sexual selection on males show relatively higher species richness. Thus, our data support the hypothesis that sexual selection elevates species richness. This could occur either by promoting speciation and/or by protecting species against extinction. © 2018 The Author(s).

A unifying framework for quantifying the nature of animal interactions.

PubMed

Potts, Jonathan R; Mokross, Karl; Lewis, Mark A

2014-07-06

Collective phenomena, whereby agent-agent interactions determine spatial patterns, are ubiquitous in the animal kingdom. On the other hand, movement and space use are also greatly influenced by the interactions between animals and their environment. Despite both types of interaction fundamentally influencing animal behaviour, there has hitherto been no unifying framework for the models proposed in both areas. Here, we construct a general method for inferring population-level spatial patterns from underlying individual movement and interaction processes, a key ingredient in building a statistical mechanics for ecological systems. We show that resource selection functions, as well as several examples of collective motion models, arise as special cases of our framework, thus bringing together resource selection analysis and collective animal behaviour into a single theory. In particular, we focus on combining the various mechanistic models of territorial interactions in the literature with step selection functions, by incorporating interactions into the step selection framework and demonstrating how to derive territorial patterns from the resulting models. We demonstrate the efficacy of our model by application to a population of insectivore birds in the Amazon rainforest. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Sperm selection in natural conception: what can we learn from Mother Nature to improve assisted reproduction outcomes?

PubMed Central

Sakkas, Denny; Ramalingam, Mythili; Garrido, Nicolas; Barratt, Christopher L.R.

2015-01-01

BACKGROUND In natural conception only a few sperm cells reach the ampulla or the site of fertilization. This population is a selected group of cells since only motile cells can pass through cervical mucus and gain initial entry into the female reproductive tract. In animals, some studies indicate that the sperm selected by the reproductive tract and recovered from the uterus and the oviducts have higher fertilization rates but this is not a universal finding. Some species show less discrimination in sperm selection and abnormal sperm do arrive at the oviduct. In contrast, assisted reproductive technologies (ART) utilize a more random sperm population. In this review we contrast the journey of the spermatozoon in vivo and in vitro and discuss this in the context of developing new sperm preparation and selection techniques for ART. METHODS A review of the literature examining characteristics of the spermatozoa selected in vivo is compared with recent developments in in vitro selection and preparation methods. Contrasts and similarities are presented. RESULTS AND CONCLUSIONS New technologies are being developed to aid in the diagnosis, preparation and selection of spermatozoa in ART. To date progress has been frustrating and these methods have provided variable benefits in improving outcomes after ART. It is more likely that examining the mechanisms enforced by nature will provide valuable information in regard to sperm selection and preparation techniques in vitro. Identifying the properties of those spermatozoa which do reach the oviduct will also be important for the development of more effective tests of semen quality. In this review we examine the value of sperm selection to see how much guidance for ART can be gleaned from the natural selection processes in vivo. PMID:26386468

Pairing Animal Cartoon Characters With Produce Stimulates Selection Among Child Zoo Visitors

PubMed Central

Karpyn, Allison; Allen, Michael; Marks, Samantha; Filion, Nicole; Humphrey, Debora; Ye, Ai; May, Henry; Gardner, Meryl P.

2017-01-01

In order to address the pervasive trend of underconsumption of fruits and vegetables among children, we examined the hypothesis that children would be more likely to select fruits (apple slices, bananas, and oranges) and vegetables (baby carrots) when paired with animal cartoon image than when available without the character image. Tested in a randomized experiment using counterbalancing, products were arranged on two tables at two separate family fun nights held at a local zoo. Animal character produce parings were manipulated by placing one of two animals (tamarin or iguana) next to two of the four fruit or vegetable selections at each table, and by changing when available without the image. In total, 755 produce selections were made. Significantly more products paired with a character were selected (62.38%) than the same products, not paired (37.62%), χ2 = 46.32, df = 1, p < .001. The odds ratio of the treatment versus control was 1.66 (i.e., 471/284), indicating that children were 66% more likely to select a snack when paired with an animal cartoon. Study findings highlight the positive impact of animal cartoons on children’s fruit and vegetable snack selections, and results suggest the potential for using animal cartoons to encourage fruit and vegetable selection for children. PMID:27866159

Pairing Animal Cartoon Characters With Produce Stimulates Selection Among Child Zoo Visitors.

PubMed

Karpyn, Allison; Allen, Michael; Marks, Samantha; Filion, Nicole; Humphrey, Debora; Ye, Ai; May, Henry; Gardner, Meryl P

2017-08-01

In order to address the pervasive trend of underconsumption of fruits and vegetables among children, we examined the hypothesis that children would be more likely to select fruits (apple slices, bananas, and oranges) and vegetables (baby carrots) when paired with animal cartoon image than when available without the character image. Tested in a randomized experiment using counterbalancing, products were arranged on two tables at two separate family fun nights held at a local zoo. Animal character produce parings were manipulated by placing one of two animals (tamarin or iguana) next to two of the four fruit or vegetable selections at each table, and by changing when available without the image. In total, 755 produce selections were made. Significantly more products paired with a character were selected (62.38%) than the same products, not paired (37.62%), χ 2 = 46.32, df = 1, p < .001. The odds ratio of the treatment versus control was 1.66 (i.e., 471/284), indicating that children were 66% more likely to select a snack when paired with an animal cartoon. Study findings highlight the positive impact of animal cartoons on children's fruit and vegetable snack selections, and results suggest the potential for using animal cartoons to encourage fruit and vegetable selection for children.

Animal Detection in Natural Images: Effects of Color and Image Database

PubMed Central

Zhu, Weina; Drewes, Jan; Gegenfurtner, Karl R.

2013-01-01

The visual system has a remarkable ability to extract categorical information from complex natural scenes. In order to elucidate the role of low-level image features for the recognition of objects in natural scenes, we recorded saccadic eye movements and event-related potentials (ERPs) in two experiments, in which human subjects had to detect animals in previously unseen natural images. We used a new natural image database (ANID) that is free of some of the potential artifacts that have plagued the widely used COREL images. Color and grayscale images picked from the ANID and COREL databases were used. In all experiments, color images induced a greater N1 EEG component at earlier time points than grayscale images. We suggest that this influence of color in animal detection may be masked by later processes when measuring reation times. The ERP results of go/nogo and forced choice tasks were similar to those reported earlier. The non-animal stimuli induced bigger N1 than animal stimuli both in the COREL and ANID databases. This result indicates ultra-fast processing of animal images is possible irrespective of the particular database. With the ANID images, the difference between color and grayscale images is more pronounced than with the COREL images. The earlier use of the COREL images might have led to an underestimation of the contribution of color. Therefore, we conclude that the ANID image database is better suited for the investigation of the processing of natural scenes than other databases commonly used. PMID:24130744

Immunological characteristics and response to lipopolysaccharide of mouse lines selectively bred with natural and acquired immunities.

PubMed

Narahara, Hiroki; Sakai, Eri; Katayama, Masafumi; Ohtomo, Yukiko; Yamamoto, Kanako; Takemoto, Miki; Aso, Hisashi; Ohwada, Shyuichi; Mohri, Yasuaki; Nishimori, Katsuhiko; Isogai, Emiko; Yamaguchi, Takahiro; Fukuda, Tomokazu

2012-05-01

Genetic improvement of resistance to infectious diseases is a challenging goal in animal breeding. Infection resistance involves multiple immunological characteristics, including natural and acquired immunity. In the present study, we developed an experimental model based on genetic selection, to improve immunological phenotypes. We selectively established three mouse lines based on phagocytic activity, antibody production and the combination of these two phenotypes. We analyzed the immunological characteristics of these lines using a lipopolysaccharide (LPS), which is one of the main components of Gram-negative bacteria. An intense immunological reaction was induced in each of the three mouse lines. Severe loss of body weight and liver damage were observed, and a high level of cytokine messenger RNA was detected in the liver tissue. The mouse line established using a combination of the two selection standards showed unique characteristics relative to the mouse lines selected on the basis of a single phenotype. Our results indicate that genetic selection and breeding is effective, even for immunological phenotypes with a relatively low heritability. Thus, it may be possible to improve resistance to infectious diseases by means of genetic selection. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Natural selection in chemical evolution.

PubMed

Fernando, Chrisantha; Rowe, Jonathan

2007-07-07

We propose that chemical evolution can take place by natural selection if a geophysical process is capable of heterotrophic formation of liposomes that grow at some base rate, divide by external agitation, and are subject to stochastic chemical avalanches, in the absence of nucleotides or any monomers capable of modular heredity. We model this process using a simple hill-climbing algorithm, and an artificial chemistry that is unique in exhibiting conservation of mass and energy in an open thermodynamic system. Selection at the liposome level results in the stabilization of rarely occurring molecular autocatalysts that either catalyse or are consumed in reactions that confer liposome level fitness; typically they contribute in parallel to an increasingly conserved intermediary metabolism. Loss of competing autocatalysts can sometimes be adaptive. Steady-state energy flux by the individual increases due to the energetic demands of growth, but also of memory, i.e. maintaining variations in the chemical network. Self-organizing principles such as those proposed by Kauffman, Fontana, and Morowitz have been hypothesized as an ordering principle in chemical evolution, rather than chemical evolution by natural selection. We reject those notions as either logically flawed or at best insufficient in the absence of natural selection. Finally, a finite population model without elitism shows the practical evolutionary constraints for achieving chemical evolution by natural selection in the lab.

Serotonin, behavior, and natural selection in New World monkeys.

PubMed

Reales, Guillermo; Paixão-Côrtes, Vanessa R; Cybis, Gabriela B; Gonçalves, Gislene L; Pissinatti, Alcides; Salzano, Francisco M; Bortolini, Maria CÁtira

2018-06-26

Traits that undergo massive natural selection pressure, with multiple events of positive selection, are hard to find. Social behaviour, in social animals, is crucial for survival, and genetic networks involved in behaviour, such as those of serotonin (5-HT) and other neurotransmitters, must be the target of natural selection. Here, we used molecular analyses to search for signals of positive selection in the 5-HT system and found such signals in the M3-M4 intracellular domain of the 5-HT3A serotonin receptor subunit (HTR3A) in primates. We detected four amino acid sites with signs of putatively positive selection (398, 403, 432 and 416); the first three showed indications of being selected in New World monkeys (NWM, Platyrrhini), specifically in the Callitrichinae branch. Additionally, we searched for associations of these amino acid variants with social behavioural traits (i.e. sex-biased dispersal, dominance and social monogamy) using classical and Bayesian methods, and found statistically significant associations for unbiased sex dispersal (398L and 416S), unbiased sex dominance (416S) and social monogamy (416S), as well as significant positive correlation between female dispersal and 403G. Furthermore, we found putatively functional protein motifs determined by three selected sites, of which we highlight a ligand motif to GSK3 in the 416S variant, appearing only in Platyrrhini. 5-HT, 5-HT3A receptor and GSK3 are part of a network that participates in neurodevelopment and regulates behaviour, among other functions. We suggest that these genetic variations, together with those found in other neurotransmitter systems, must contribute to adaptive behaviours and consequently to fitness in NWMs. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Sexual dichromatism in frogs: natural selection, sexual selection and unexpected diversity.

PubMed

Bell, Rayna C; Zamudio, Kelly R

2012-12-07

Sexual dichromatism, a form of sexual dimorphism in which males and females differ in colour, is widespread in animals but has been predominantly studied in birds, fishes and butterflies. Moreover, although there are several proposed evolutionary mechanisms for sexual dichromatism in vertebrates, few studies have examined this phenomenon outside the context of sexual selection. Here, we describe unexpectedly high diversity of sexual dichromatism in frogs and create a comparative framework to guide future analyses of the evolution of these sexual colour differences. We review what is known about evolution of colour dimorphism in frogs, highlight alternative mechanisms that may contribute to the evolution of sexual colour differences, and compare them to mechanisms active in other major groups of vertebrates. In frogs, sexual dichromatism can be dynamic (temporary colour change in males) or ontogenetic (permanent colour change in males or females). The degree and the duration of sexual colour differences vary greatly across lineages, and we do not detect phylogenetic signal in the distribution of this trait, therefore frogs provide an opportunity to investigate the roles of natural and sexual selection across multiple independent derivations of sexual dichromatism.

Ethical and Animal Welfare Considerations in Relation to Species Selection for Animal Experimentation.

PubMed

Webster, John

2014-12-03

Ethical principles governing the conduct of experiments with animals are reviewed, especially those relating to the choice of species. Legislation requires that the potential harm to animals arising from any procedure should be assessed in advance and justified in terms of its possible benefit to society. Potential harms may arise both from the procedures and the quality of the animals' lifetime experience. The conventional approach to species selection is to use animals with the "lowest degree of neurophysiological sensitivity". However; this concept should be applied with extreme caution in the light of new knowledge. The capacity to experience pain may be similar in mammals, birds and fish. The capacity to suffer from fear is governed more by sentience than cognitive ability, so it cannot be assumed that rodents or farm animals suffer less than dogs or primates. I suggest that it is unethical to base the choice of species for animal experimentation simply on the basis that it will cause less distress within society. A set of responsibilities is outlined for each category of moral agent. These include regulators, operators directly concerned with the conduct of scientific experiments and toxicology trials, veterinarians and animal care staff; and society at large.

Natural Selection on Individual Variation in Tolerance of Gastrointestinal Nematode Infection

PubMed Central

Hayward, Adam D.; Nussey, Daniel H.; Wilson, Alastair J.; Berenos, Camillo; Pilkington, Jill G.; Watt, Kathryn A.; Pemberton, Josephine M.; Graham, Andrea L.

2014-01-01

Hosts may mitigate the impact of parasites by two broad strategies: resistance, which limits parasite burden, and tolerance, which limits the fitness or health cost of increasing parasite burden. The degree and causes of variation in both resistance and tolerance are expected to influence host–parasite evolutionary and epidemiological dynamics and inform disease management, yet very little empirical work has addressed tolerance in wild vertebrates. Here, we applied random regression models to longitudinal data from an unmanaged population of Soay sheep to estimate individual tolerance, defined as the rate of decline in body weight with increasing burden of highly prevalent gastrointestinal nematode parasites. On average, individuals lost weight as parasite burden increased, but whereas some lost weight slowly as burden increased (exhibiting high tolerance), other individuals lost weight significantly more rapidly (exhibiting low tolerance). We then investigated associations between tolerance and fitness using selection gradients that accounted for selection on correlated traits, including body weight. We found evidence for positive phenotypic selection on tolerance: on average, individuals who lost weight more slowly with increasing parasite burden had higher lifetime breeding success. This variation did not have an additive genetic basis. These results reveal that selection on tolerance operates under natural conditions. They also support theoretical predictions for the erosion of additive genetic variance of traits under strong directional selection and fixation of genes conferring tolerance. Our findings provide the first evidence of selection on individual tolerance of infection in animals and suggest practical applications in animal and human disease management in the face of highly prevalent parasites. PMID:25072883

Contemporary evolution during invasion: evidence for differentiation, natural selection, and local adaptation.

PubMed

Colautti, Robert I; Lau, Jennifer A

2015-05-01

Biological invasions are 'natural' experiments that can improve our understanding of contemporary evolution. We evaluate evidence for population differentiation, natural selection and adaptive evolution of invading plants and animals at two nested spatial scales: (i) among introduced populations (ii) between native and introduced genotypes. Evolution during invasion is frequently inferred, but rarely confirmed as adaptive. In common garden studies, quantitative trait differentiation is only marginally lower (~3.5%) among introduced relative to native populations, despite genetic bottlenecks and shorter timescales (i.e. millennia vs. decades). However, differentiation between genotypes from the native vs. introduced range is less clear and confounded by nonrandom geographic sampling; simulations suggest this causes a high false-positive discovery rate (>50%) in geographically structured populations. Selection differentials (¦s¦) are stronger in introduced than in native species, although selection gradients (¦β¦) are not, consistent with introduced species experiencing weaker genetic constraints. This could facilitate rapid adaptation, but evidence is limited. For example, rapid phenotypic evolution often manifests as geographical clines, but simulations demonstrate that nonadaptive trait clines can evolve frequently during colonization (~two-thirds of simulations). Additionally, QST-FST studies may often misrepresent the strength and form of natural selection acting during invasion. Instead, classic approaches in evolutionary ecology (e.g. selection analysis, reciprocal transplant, artificial selection) are necessary to determine the frequency of adaptive evolution during invasion and its influence on establishment, spread and impact of invasive species. These studies are rare but crucial for managing biological invasions in the context of global change. © 2015 John Wiley & Sons Ltd.

Natural selection. IV. The Price equation*

PubMed Central

Frank, Steven A.

2012-01-01

The Price equation partitions total evolutionary change into two components. The first component provides an abstract expression of natural selection. The second component subsumes all other evolutionary processes, including changes during transmission. The natural selection component is often used in applications. Those applications attract widespread interest for their simplicity of expression and ease of interpretation. Those same applications attract widespread criticism by dropping the second component of evolutionary change and by leaving unspecified the detailed assumptions needed for a complete study of dynamics. Controversies over approximation and dynamics have nothing to do with the Price equation itself, which is simply a mathematical equivalence relation for total evolutionary change expressed in an alternative form. Disagreements about approach have to do with the tension between the relative valuation of abstract versus concrete analyses. The Price equation’s greatest value has been on the abstract side, particularly the invariance relations that illuminate the understanding of natural selection. Those abstract insights lay the foundation for applications in terms of kin selection, information theory interpretations of natural selection, and partitions of causes by path analysis. I discuss recent critiques of the Price equation by Nowak and van Veelen. PMID:22487312

Microsatellites as targets of natural selection.

PubMed

Haasl, Ryan J; Payseur, Bret A

2013-02-01

The ability to survey polymorphism on a genomic scale has enabled genome-wide scans for the targets of natural selection. Theory that connects patterns of genetic variation to evidence of natural selection most often assumes a diallelic locus and no recurrent mutation. Although these assumptions are suitable to selection that targets single nucleotide variants, fundamentally different types of mutation generate abundant polymorphism in genomes. Moreover, recent empirical results suggest that mutationally complex, multiallelic loci including microsatellites and copy number variants are sometimes targeted by natural selection. Given their abundance, the lack of inference methods tailored to the mutational peculiarities of these types of loci represents a notable gap in our ability to interrogate genomes for signatures of natural selection. Previous theoretical investigations of mutation-selection balance at multiallelic loci include assumptions that limit their application to inference from empirical data. Focusing on microsatellites, we assess the dynamics and population-level consequences of selection targeting mutationally complex variants. We develop general models of a multiallelic fitness surface, a realistic model of microsatellite mutation, and an efficient simulation algorithm. Using these tools, we explore mutation-selection-drift equilibrium at microsatellites and investigate the mutational history and selective regime of the microsatellite that causes Friedreich's ataxia. We characterize microsatellite selective events by their duration and cost, note similarities to sweeps from standing point variation, and conclude that it is premature to label microsatellites as ubiquitous agents of efficient adaptive change. Together, our models and simulation algorithm provide a powerful framework for statistical inference, which can be used to test the neutrality of microsatellites and other multiallelic variants.

Microsatellites as Targets of Natural Selection

PubMed Central

Haasl, Ryan J.; Payseur, Bret A.

2013-01-01

The ability to survey polymorphism on a genomic scale has enabled genome-wide scans for the targets of natural selection. Theory that connects patterns of genetic variation to evidence of natural selection most often assumes a diallelic locus and no recurrent mutation. Although these assumptions are suitable to selection that targets single nucleotide variants, fundamentally different types of mutation generate abundant polymorphism in genomes. Moreover, recent empirical results suggest that mutationally complex, multiallelic loci including microsatellites and copy number variants are sometimes targeted by natural selection. Given their abundance, the lack of inference methods tailored to the mutational peculiarities of these types of loci represents a notable gap in our ability to interrogate genomes for signatures of natural selection. Previous theoretical investigations of mutation-selection balance at multiallelic loci include assumptions that limit their application to inference from empirical data. Focusing on microsatellites, we assess the dynamics and population-level consequences of selection targeting mutationally complex variants. We develop general models of a multiallelic fitness surface, a realistic model of microsatellite mutation, and an efficient simulation algorithm. Using these tools, we explore mutation-selection-drift equilibrium at microsatellites and investigate the mutational history and selective regime of the microsatellite that causes Friedreich’s ataxia. We characterize microsatellite selective events by their duration and cost, note similarities to sweeps from standing point variation, and conclude that it is premature to label microsatellites as ubiquitous agents of efficient adaptive change. Together, our models and simulation algorithm provide a powerful framework for statistical inference, which can be used to test the neutrality of microsatellites and other multiallelic variants. PMID:23104080

Application of genomic selection in farm animal breeding.

PubMed

Tan, Cheng; Bian, Cheng; Yang, Da; Li, Ning; Wu, Zhen-Fang; Hu, Xiao-Xiang

2017-11-20

Genomic selection (GS) has become a widely accepted method in animal breeding to genetically improve economic traits. With the declining costs of high-density SNP chips and next-generation sequencing, GS has been applied in dairy cattle, swine, poultry and other animals and gained varying degrees of success. Currently, major challenges in GS studies include further reducing the cost of genome-wide SNP genotyping and improving the predictive accuracy of genomic estimated breeding value (GEBV). In this review, we summarize various methods for genome-wide SNP genotyping and GEBV prediction, and give a brief introduction of GS in livestock and poultry breeding. This review will provide a reference for further implementation of GS in farm animal breeding.

Sensitivity of Students to the Natural Environment, Animals, Social Problems and Cultural Heritage

ERIC Educational Resources Information Center

Kurtdede Fidan, Nuray

2016-01-01

The study aims to determine the sensitivity levels of fourth-grade students to the natural environment, animals, social concerns and cultural heritage. Besides, it has been investigated whether some personal characteristics of the students have differentiating effect on the views related to the sensitivity to the natural environment, animals,…

Animals and Us: How We Live Together. Nature. Teacher's Guide.

ERIC Educational Resources Information Center

Barker, Lucia; Brown, Jordan

This curriculum guide was developed for use with public television's Nature series. The materials in the guide are designed to help students actively participate in the study and experience of nature. Students are encouraged to view the programs as naturalists would, observing animals in their environment, noting their behavior, and drawing…

Natural selection stops the evolution of male attractiveness

PubMed Central

Hine, Emma; McGuigan, Katrina; Blows, Mark W.

2011-01-01

Sexual selection in natural populations acts on highly heritable traits and tends to be relatively strong, implicating sexual selection as a causal agent in many phenotypic radiations. Sexual selection appears to be ineffectual in promoting phenotypic divergence among contemporary natural populations, however, and there is little evidence from artificial selection experiments that sexual fitness can evolve. Here, we demonstrate that a multivariate male trait preferred by Drosophila serrata females can respond to selection and results in the maintenance of male mating success. The response to selection was associated with a gene of major effect increasing in frequency from 12 to 35% in seven generations. No further response to selection, or increase in frequency of the major gene, was observed between generations 7 and 11, indicating an evolutionary limit had been reached. Genetic analyses excluded both depletion of genetic variation and overdominance as causes of the evolutionary limit. Relaxing artificial selection resulted in the loss of 52% of the selection response after a further five generations, demonstrating that the response under artificial sexual selection was opposed by antagonistic natural selection. We conclude that male D. serrata sexually selected traits, and attractiveness to D. serrata females conferred by these traits, were held at an evolutionary limit by the lack of genetic variation that would allow an increase in sexual fitness while simultaneously maintaining nonsexual fitness. Our results suggest that sexual selection is unlikely to cause divergence among natural populations without a concomitant change in natural selection, a conclusion consistent with observational evidence from natural populations. PMID:21321197

Natural selection. IV. The Price equation.

PubMed

Frank, S A

2012-06-01

The Price equation partitions total evolutionary change into two components. The first component provides an abstract expression of natural selection. The second component subsumes all other evolutionary processes, including changes during transmission. The natural selection component is often used in applications. Those applications attract widespread interest for their simplicity of expression and ease of interpretation. Those same applications attract widespread criticism by dropping the second component of evolutionary change and by leaving unspecified the detailed assumptions needed for a complete study of dynamics. Controversies over approximation and dynamics have nothing to do with the Price equation itself, which is simply a mathematical equivalence relation for total evolutionary change expressed in an alternative form. Disagreements about approach have to do with the tension between the relative valuation of abstract versus concrete analyses. The Price equation's greatest value has been on the abstract side, particularly the invariance relations that illuminate the understanding of natural selection. Those abstract insights lay the foundation for applications in terms of kin selection, information theory interpretations of natural selection and partitions of causes by path analysis. I discuss recent critiques of the Price equation by Nowak and van Veelen. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

[Polish legal terms of animal-based research - selected aspects].

PubMed

Poznański, Paweł; Niedźwiecki, Sławomir

2014-01-01

Animal-based models used in biomedical sciences allow to perform research that, conducted on humans, would be highly problematic because of bioethical and technical issues. Contemporary researchers race can lead to abuse, hence the need for special law regulations regarding this subject. This necessity reflected both in the EU and Polish legislation, and is rooted in the philosophical and moral achievements of Europe. EU legislation in this case takes the form of directives implemented in the legal systems of the member states. Polish tradition of legislative approach to animal-based research is long. In 1959 the wide attempt to regulate this matter was undertaken. Until 2005, the nature of the matter had been regulated by the Polish animal protection law. Currently, details concerning animal-based-research are regulated by the animal experiments law (2005). The elapsed time since enactment allowed doctrine and judicature to reveal capabilities and vulnerabilities of the law.

Companion Animals, Natural Disasters and the Law: An Australian Perspective

PubMed Central

White, Steven

2012-01-01

Simple Summary One of the issues raised by recent natural disasters in Australia is the management of companion animal welfare in disaster planning, response and recovery. Official inquiries following these disasters uncovered a number of shortcomings in addressing the management of animal welfare issues. This article suggests that despite some reform following these events, disaster management still fails to take seriously the interests of companion animals. Abstract This article examines the regulation of companion animal welfare during disasters, with some context provided by two recent major disaster events in Australia. Important general lessons for improved disaster management were identified in subsequent inquiries. However, the interests of companion animals continue to be inadequately addressed. This is because key assumptions underpinning disaster planning for companion animals—the primacy of human interests over animal interests and that individuals will properly address companion animal needs during times of disaster—are open to question. In particular these assumptions fail to recognise the inherent value of companion animals, underestimate the strong bond shared by some owners and their animals and, at the same time, overestimate the capacity of some owners to adequately meet the needs of their animals. PMID:26487028

The Cynomolgus Macaque Natural History Model of Pneumonic Tularemia for Predicting Clinical Efficacy Under the Animal Rule

PubMed Central

Guina, Tina; Lanning, Lynda L.; Omland, Kristian S.; Williams, Mark S.; Wolfraim, Larry A.; Heyse, Stephen P.; Houchens, Christopher R.; Sanz, Patrick; Hewitt, Judith A.

2018-01-01

Francisella tularensis is a highly infectious Gram-negative bacterium that is the etiologic agent of tularemia in animals and humans and a Tier 1 select agent. The natural incidence of pneumonic tularemia worldwide is very low; therefore, it is not feasible to conduct clinical efficacy testing of tularemia medical countermeasures (MCM) in human populations. Development and licensure of tularemia therapeutics and vaccines need to occur under the Food and Drug Administration's (FDA's) Animal Rule under which efficacy studies are conducted in well-characterized animal models that reflect the pathophysiology of human disease. The Tularemia Animal Model Qualification (AMQ) Working Group is seeking qualification of the cynomolgus macaque (Macaca fascicularis) model of pneumonic tularemia under Drug Development Tools Qualification Programs with the FDA based upon the results of studies described in this manuscript. Analysis of data on survival, average time to death, average time to fever onset, average interval between fever and death, and bacteremia; together with summaries of clinical signs, necropsy findings, and histopathology from the animals exposed to aerosolized F. tularensis Schu S4 in five natural history studies and one antibiotic efficacy study form the basis for the proposed cynomolgus macaque model. Results support the conclusion that signs of pneumonic tularemia in cynomolgus macaques exposed to 300–3,000 colony forming units (cfu) aerosolized F. tularensis Schu S4, under the conditions described herein, and human pneumonic tularemia cases are highly similar. Animal age, weight, and sex of animals challenged with 300–3,000 cfu Schu S4 did not impact fever onset in studies described herein. This study summarizes critical parameters and endpoints of a well-characterized cynomolgus macaque model of pneumonic tularemia and demonstrates this model is appropriate for qualification, and for testing efficacy of tularemia therapeutics under Animal Rule. PMID

Selectively De-animating and Stabilizing Videos

DTIC Science & Technology

2014-12-11

unexpectedly engaging. They are now widely seen in major online newspapers, magazines, advertising and retail websites. Our cinemagraph examples can be seen...total, we seek a labeling that minimizes ∑ p1,p2 Φ(p1, p2, λ1, λ2) (3.11) CHAPTER 3. SELECTIVELY DE-ANIMATING VIDEOS 26 Model K Model S Beer Glass...Our next four examples are seamlessly looping cinemagraphs (Figure 3.6). Beer and Glass: We have generated two cinemagraphs that immobilize glassware

Using the Animal Model to Accelerate Response to Selection in a Self-Pollinating Crop

PubMed Central

Cowling, Wallace A.; Stefanova, Katia T.; Beeck, Cameron P.; Nelson, Matthew N.; Hargreaves, Bonnie L. W.; Sass, Olaf; Gilmour, Arthur R.; Siddique, Kadambot H. M.

2015-01-01

We used the animal model in S0 (F1) recurrent selection in a self-pollinating crop including, for the first time, phenotypic and relationship records from self progeny, in addition to cross progeny, in the pedigree. We tested the model in Pisum sativum, the autogamous annual species used by Mendel to demonstrate the particulate nature of inheritance. Resistance to ascochyta blight (Didymella pinodes complex) in segregating S0 cross progeny was assessed by best linear unbiased prediction over two cycles of selection. Genotypic concurrence across cycles was provided by pure-line ancestors. From cycle 1, 102/959 S0 plants were selected, and their S1 self progeny were intercrossed and selfed to produce 430 S0 and 575 S2 individuals that were evaluated in cycle 2. The analysis was improved by including all genetic relationships (with crossing and selfing in the pedigree), additive and nonadditive genetic covariances between cycles, fixed effects (cycles and spatial linear trends), and other random effects. Narrow-sense heritability for ascochyta blight resistance was 0.305 and 0.352 in cycles 1 and 2, respectively, calculated from variance components in the full model. The fitted correlation of predicted breeding values across cycles was 0.82. Average accuracy of predicted breeding values was 0.851 for S2 progeny of S1 parent plants and 0.805 for S0 progeny tested in cycle 2, and 0.878 for S1 parent plants for which no records were available. The forecasted response to selection was 11.2% in the next cycle with 20% S0 selection proportion. This is the first application of the animal model to cyclic selection in heterozygous populations of selfing plants. The method can be used in genomic selection, and for traits measured on S0-derived bulks such as grain yield. PMID:25943522

Overcrowding and Population Growth: The Nature and Relevance of Animal Behavior.

ERIC Educational Resources Information Center

Stettner, Laurence J.

This paper provides a descriptive overview of research on the consequences of overcrowding and the development of high population densities in animals, and speculates on the relevance of these studies for similar human phenomena. Three major foci are distinguished: (1) the effect of high population densities on animal behavior; (2) the nature of…

Natural Selection as Coarsening

NASA Astrophysics Data System (ADS)

Smerlak, Matteo

2017-11-01

Analogies between evolutionary dynamics and statistical mechanics, such as Fisher's second-law-like "fundamental theorem of natural selection" and Wright's "fitness landscapes", have had a deep and fruitful influence on the development of evolutionary theory. Here I discuss a new conceptual link between evolution and statistical physics. I argue that natural selection can be viewed as a coarsening phenomenon, similar to the growth of domain size in quenched magnets or to Ostwald ripening in alloys and emulsions. In particular, I show that the most remarkable features of coarsening—scaling and self-similarity—have strict equivalents in evolutionary dynamics. This analogy has three main virtues: it brings a set of well-developed mathematical tools to bear on evolutionary dynamics; it suggests new problems in theoretical evolution; and it provides coarsening physics with a new exactly soluble model.

Natural Selection as Coarsening

NASA Astrophysics Data System (ADS)

Smerlak, Matteo

2018-07-01

Analogies between evolutionary dynamics and statistical mechanics, such as Fisher's second-law-like "fundamental theorem of natural selection" and Wright's "fitness landscapes", have had a deep and fruitful influence on the development of evolutionary theory. Here I discuss a new conceptual link between evolution and statistical physics. I argue that natural selection can be viewed as a coarsening phenomenon, similar to the growth of domain size in quenched magnets or to Ostwald ripening in alloys and emulsions. In particular, I show that the most remarkable features of coarsening—scaling and self-similarity—have strict equivalents in evolutionary dynamics. This analogy has three main virtues: it brings a set of well-developed mathematical tools to bear on evolutionary dynamics; it suggests new problems in theoretical evolution; and it provides coarsening physics with a new exactly soluble model.

Populations, Natural Selection, and Applied Organizational Science.

ERIC Educational Resources Information Center

McKelvey, Bill; Aldrich, Howard

1983-01-01

Deficiencies in existing models in organizational science may be remedied by applying the population approach, with its concepts of taxonomy, classification, evolution, and population ecology; and natural selection theory, with its principles of variation, natural selection, heredity, and struggle for existence, to the idea of organizational forms…

Comparing Patterns of Natural Selection across Species Using Selective Signatures

PubMed Central

Shapiro, B. Jesse; Alm, Eric J

2008-01-01

Comparing gene expression profiles over many different conditions has led to insights that were not obvious from single experiments. In the same way, comparing patterns of natural selection across a set of ecologically distinct species may extend what can be learned from individual genome-wide surveys. Toward this end, we show how variation in protein evolutionary rates, after correcting for genome-wide effects such as mutation rate and demographic factors, can be used to estimate the level and types of natural selection acting on genes across different species. We identify unusually rapidly and slowly evolving genes, relative to empirically derived genome-wide and gene family-specific background rates for 744 core protein families in 30 γ-proteobacterial species. We describe the pattern of fast or slow evolution across species as the “selective signature” of a gene. Selective signatures represent a profile of selection across species that is predictive of gene function: pairs of genes with correlated selective signatures are more likely to share the same cellular function, and genes in the same pathway can evolve in concert. For example, glycolysis and phenylalanine metabolism genes evolve rapidly in Idiomarina loihiensis, mirroring an ecological shift in carbon source from sugars to amino acids. In a broader context, our results suggest that the genomic landscape is organized into functional modules even at the level of natural selection, and thus it may be easier than expected to understand the complex evolutionary pressures on a cell. PMID:18266472

Ethical and Animal Welfare Considerations in Relation to Species Selection for Animal Experimentation

PubMed Central

Webster, John

2014-01-01

Simple Summary When making a choice of species for animal experimentation we must balance its suitability as a model for human medicine against the potential harms to the animals both from the procedures and the quality of their lifetime experience. The capacity to experience pain may be similar in mammals, birds and fish. The capacity to suffer from fear is governed more by sentience than cognitive ability, so it cannot be assumed that rodents or farm animals suffer less than dogs or primates. I suggest that it is unethical to base the choice of species for animal experimentation simply on the basis that it will cause less distress within society. Abstract Ethical principles governing the conduct of experiments with animals are reviewed, especially those relating to the choice of species. Legislation requires that the potential harm to animals arising from any procedure should be assessed in advance and justified in terms of its possible benefit to society. Potential harms may arise both from the procedures and the quality of the animals’ lifetime experience. The conventional approach to species selection is to use animals with the “lowest degree of neurophysiological sensitivity”. However; this concept should be applied with extreme caution in the light of new knowledge. The capacity to experience pain may be similar in mammals, birds and fish. The capacity to suffer from fear is governed more by sentience than cognitive ability, so it cannot be assumed that rodents or farm animals suffer less than dogs or primates. I suggest that it is unethical to base the choice of species for animal experimentation simply on the basis that it will cause less distress within society. A set of responsibilities is outlined for each category of moral agent. These include regulators, operators directly concerned with the conduct of scientific experiments and toxicology trials, veterinarians and animal care staff; and society at large. PMID:26479009

Selection of artificial gravity by animals during suborbital rocket flights.

PubMed

Lange, K O; Belleville, R E; Clark, F C

1975-06-01

White rats selected preferred artificial gravity levels by locomotion in centrifuges consisting of two runways mounted in the nose of sounding rockets. Roll rate of the Aerobee 150A rocket was designed to produce an angular velocity of 45 r.p.m. during 5 min of free-fall, providing a gravity range range from 0.3 to 1.5 G depending on a subject's runway position. One animal was released at the high and one at the low gravity position in each flight. Animal positions were continuously recorded. Flight subjects were selected from about 100 trained animals adapted to the simulated launch environment for several months. In two flights excessive rollrates produced gravity ranges above the designed limits. In two other flights the desired range was produced. Locomotion patterns during these flights were similar. All four animals explored the entire available G-range. One rat settled at 0.4 G after 2 min; the others crossed the 1-G location in progressively narrower excursions and were near earth gravity at the end of the test period. Data were more varible than in laboratory tests above 1 G and the observation periods were necessarily few and short. Tentatively, however, the data suggest that normal earth-reared rats select earth gravity when available magnitudes include values above and below 1 B. Modification of gravity preference by prolonged exposure to higher or lower levels remains a possibility.

Caring during crisis: animal welfare during pandemics and natural disasters.

PubMed

Millman, Suzanne T

2008-01-01

From April 29 to May 1, 2007, the University of Guelph hosted a symposium, Caring During Crisis: Animal Welfare During Pandemics and Natural Disasters, with the objectives (a) of raising awareness about how nonhuman animals and the people who care for them are affected during emergencies and (b) of sharing knowledge about how animal welfare may be addressed during these situations. The symposium attracted 150 participants, representing 71 organizations from across Canada, the United States, the United Kingdom, Australia, Chile, and the Cayman Islands. The audience also brought a range of perspectives to the issues - from individuals representing animal protection and commodity organizations to municipal government officials responsible for community safety and correctional services; many of these individuals had little or no animal experience. To take advantage of this diverse audience and range of interests, the symposium was structured with formal presentations by internationally recognized experts, followed by panel discussions at the end of each session to facilitate contributions by the audience. At the conclusion of the 3 days, it was clear that our emotional, economic, and ecological relationships with animals require thoughtful integration of animal care within formal policy and planning for emergency response.

A quantum of natural selection

NASA Astrophysics Data System (ADS)

Lloyd, Seth

2009-03-01

The modern evolutionary synthesis, which marries Darwin's theory of natural selection with Mendel's genetics, was developed around the same time as quantum mechanics. Is there any connection between the two?

3D animation model with augmented reality for natural science learning in elementary school

NASA Astrophysics Data System (ADS)

Hendajani, F.; Hakim, A.; Lusita, M. D.; Saputra, G. E.; Ramadhana, A. P.

2018-05-01

Many opinions from primary school students' on Natural Science are a difficult lesson. Many subjects are not easily understood by students, especially on materials that teach some theories about natural processes. Such as rain process, condensation and many other processes. The difficulty that students experience in understanding it is that students cannot imagine the things that have been taught in the material. Although there is material to practice some theories but is actually quite limited. There is also a video or simulation material in the form of 2D animated images. Understanding concepts in natural science lessons are also poorly understood by students. Natural Science learning media uses 3-dimensional animation models (3D) with augmented reality technology, which offers some visualization of science lessons. This application was created to visualize a process in Natural Science subject matter. The hope of making this application is to improve student's concept. This app is made to run on a personal computer that comes with a webcam with augmented reality. The app will display a 3D animation if the camera can recognize the marker.

Selection of artificial gravity by animals during suborbital rocket flights

NASA Technical Reports Server (NTRS)

Lange, K. O.; Belleville, R. E.; Clark, F. C.

1975-01-01

White rats selected preferred artificial gravity levels by locomotion in centrifuges consisting of two runways mounted in the nose of sounding rockets. Roll rate of the Aerobee 150A rocket was designed to produce an angular velocity of 45 rpm during 5 min of free-fall, providing a gravity range from 0.3 to 1.5 G depending on a subject's runway position. One animal was released at the high and one at the low gravity position in each flight. Animal positions were continuously recorded. Locomotion patterns during these flights were similar. All four animals explored the entire available G-range. One rat settled at 0.4 G after 2 min; the others crossed the 1-G location in progressively narrower excursions and were near earth gravity at the end of the test period. Tentatively, the data suggest that normal earth-reared rats select earth gravity when available magnitudes include values above and below 1 G. Modification of gravity preference by prolonged exposure to higher or lower levels remains a possibility.

Phenotypic selection in natural populations: what limits directional selection?

PubMed

Kingsolver, Joel G; Diamond, Sarah E

2011-03-01

Studies of phenotypic selection document directional selection in many natural populations. What factors reduce total directional selection and the cumulative evolutionary responses to selection? We combine two data sets for phenotypic selection, representing more than 4,600 distinct estimates of selection from 143 studies, to evaluate the potential roles of fitness trade-offs, indirect (correlated) selection, temporally varying selection, and stabilizing selection for reducing net directional selection and cumulative responses to selection. We detected little evidence that trade-offs among different fitness components reduced total directional selection in most study systems. Comparisons of selection gradients and selection differentials suggest that correlated selection frequently reduced total selection on size but not on other types of traits. The direction of selection on a trait often changes over time in many temporally replicated studies, but these fluctuations have limited impact in reducing cumulative directional selection in most study systems. Analyses of quadratic selection gradients indicated stabilizing selection on body size in at least some studies but provided little evidence that stabilizing selection is more common than disruptive selection for most traits or study systems. Our analyses provide little evidence that fitness trade-offs, correlated selection, or stabilizing selection strongly constrains the directional selection reported for most quantitative traits.

Natural Selection in the Field and the Classroom

ERIC Educational Resources Information Center

Andrews, Tessa Marie

2012-01-01

This dissertation examined natural selection in westslope cutthroat trout ("Oncorhynchus clarkii lewisi") and undergraduate learning in the subject area natural selection. Translocation--moving individuals to a new habitat to establish, re-establish or supplement a population--is a crucial management strategy for cutthroat trout. One of…

Secrets and lies: "selective openness" in the apparatus of animal experimentation.

PubMed

Holmberg, Tora; Ideland, Malin

2012-04-01

Researchers and other (human) actors within the apparatus of animal experimentation find themselves in a tight corner. They rely on public acceptance to promote their legitimacy and to receive funding. At the same time, those working with animal experimentation take risks by going public, fearing that the public will misunderstand their work and animal rights activists may threaten them. The dilemma that emerges between openness and secrecy is fairly prevalent in scientific culture as a whole, but the apparatus of animal experimentation presents specific patterns of technologies of secrets. The aim of the paper is to describe and analyse the meanings of secrets and openness in contemporary animal experimentation. We suggest that these secrets--or "selective openness"--can be viewed as grease in the apparatus of animal experimentation, as a unifying ingredient that permits maintenance of status quo in human/animal relations and preserves existing institutional public/ science relations.

Ferritin gene organization: differences between plants and animals suggest possible kingdom-specific selective constraints.

PubMed

Proudhon, D; Wei, J; Briat, J; Theil, E C

1996-03-01

Ferritin, a protein widespread in nature, concentrates iron approximately 10(11)-10(12)-fold above the solubility within a spherical shell of 24 subunits; it derives in plants and animals from a common ancestor (based on sequence) but displays a cytoplasmic location in animals compared to the plastid in contemporary plants. Ferritin gene regulation in plants and animals is altered by development, hormones, and excess iron; iron signals target DNA in plants but mRNA in animals. Evolution has thus conserved the two end points of ferritin gene expression, the physiological signals and the protein structure, while allowing some divergence of the genetic mechanisms. Comparison of ferritin gene organization in plants and animals, made possible by the cloning of a dicot (soybean) ferritin gene presented here and the recent cloning of two monocot (maize) ferritin genes, shows evolutionary divergence in ferritin gene organization between plants and animals but conservation among plants or among animals; divergence in the genetic mechanism for iron regulation is reflected by the absence in all three plant genes of the IRE, a highly conserved, noncoding sequence in vertebrate animal ferritin mRNA. In plant ferritin genes, the number of introns (n = 7) is higher than in animals (n = 3). Second, no intron positions are conserved when ferritin genes of plants and animals are compared, although all ferritin gene introns are in the coding region; within kingdoms, the intron positions in ferritin genes are conserved. Finally, secondary protein structure has no apparent relationship to intron/exon boundaries in plant ferritin genes, whereas in animal ferritin genes the correspondence is high. The structural differences in introns/exons among phylogenetically related ferritin coding sequences and the high conservation of the gene structure within plant or animal kingdoms of the gene structure within plant or animal kingdoms suggest that kingdom-specific functional constraints may

Natural selection. VII. History and interpretation of kin selection theory.

PubMed

Frank, S A

2013-06-01

Kin selection theory is a kind of causal analysis. The initial form of kin selection ascribed cause to costs, benefits and genetic relatedness. The theory then slowly developed a deeper and more sophisticated approach to partitioning the causes of social evolution. Controversy followed because causal analysis inevitably attracts opposing views. It is always possible to separate total effects into different component causes. Alternative causal schemes emphasize different aspects of a problem, reflecting the distinct goals, interests and biases of different perspectives. For example, group selection is a particular causal scheme with certain advantages and significant limitations. Ultimately, to use kin selection theory to analyse natural patterns and to understand the history of debates over different approaches, one must follow the underlying history of causal analysis. This article describes the history of kin selection theory, with emphasis on how the causal perspective improved through the study of key patterns of natural history, such as dispersal and sex ratio, and through a unified approach to demographic and social processes. Independent historical developments in the multivariate analysis of quantitative traits merged with the causal analysis of social evolution by kin selection. © 2013 The Author. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS system with timed and highly selective reaction monitoring.

PubMed

Zhao, Zhiyong; Liu, Na; Yang, Lingchen; Deng, Yifeng; Wang, Jianhua; Song, Suquan; Lin, Shanhai; Wu, Aibo; Zhou, Zhenlei; Hou, Jiafa

2015-09-01

Mycotoxins have the potential to enter the human food chain through carry-over of contaminants from feed into animal-derived products. The objective of the study was to develop a reliable and sensitive method for the analysis of 30 mycotoxins in animal feed and animal-derived food (meat, edible animal tissues, and milk) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the study, three extraction procedures, as well as various cleanup procedures, were evaluated to select the most suitable sample preparation procedure for different sample matrices. In addition, timed and highly selective reaction monitoring on LC-MS/MS was used to filter out isobaric matrix interferences. The performance characteristics (linearity, sensitivity, recovery, precision, and specificity) of the method were determined according to Commission Decision 2002/657/EC and 401/2006/EC. The established method was successfully applied to screening of mycotoxins in animal feed and animal-derived food. The results indicated that mycotoxin contamination in feed directly influenced the presence of mycotoxin in animal-derived food. Graphical abstract Multi-mycotoxin analysis of animal feed and animal-derived food using LC-MS/MS.

More ecological ERA: incorporating natural environmental factors and animal behavior.

PubMed

Bednarska, Agnieszka J; Jevtić, Dragan M; Laskowski, Ryszard

2013-07-01

We discuss the importance of selected natural abiotic and biotic factors in ecological risk assessment based on simplistic laboratory bioassays. Although it is impossible to include all possible natural factors in standard lower-tier ecotoxicological testing, neglecting them is not an option. Therefore, we try to identify the most important factors and advocate redesigning standard testing procedures to include theoretically most potent interactions. We also point out a few potentially important factors that have not been studied enough so far. The available data allowed us to identify temperature and O2 depletion as the most critical factors that should be included in ecotoxicity testing as soon as possible. Temporal limitations and fluctuations in food availability also appear important, but at this point more fundamental research in this area is necessary before making decisions on their inclusion in risk assessment procedures. We propose using specific experimental designs, such as Box-Behnken or Central Composite, which allow for simultaneous testing of 3 or more factors for their individual and interactive effects with greater precision and without increasing the effort and costs of tests dramatically. Factorial design can lead to more powerful tests and help to extend the validity of conclusions. Finally, ecological risk assessment procedures should include information on animal behavior, especially feeding patterns. This requires more basic studies, but already at this point adequate mechanistic effect models can be developed for some species. Copyright © 2013 SETAC.

Animal-derived natural products of Sowa Rigpa medicine: Their pharmacopoeial description, current utilization and zoological identification.

PubMed

Yeshi, Karma; Morisco, Paolo; Wangchuk, Phurpa

2017-07-31

The Bhutanese Sowa Rigpa medicine (BSM) uses animal parts in the preparation of numerous polyingredient traditional remedies. Our study reports the taxonomical identification of medicinal animals and the description of traditional uses in English medical terminologies. To taxonomically identify the medicinal animals and their derived natural products used as a zootherapeutic agents in BSM. First, the traditional textbooks were reviewed to generate a list of animal products described as ingredients. Second, animal parts that are currently used in Bhutan were identified. Third, the ethnopharmacological uses of each animal ingredients were translated into English medical terminologies by consulting Traditional Physicians, clinical assistants, pharmacognosists, and pharmacists in Bhutan. Fourth, the animal parts were taxonomically identified and their Latin names were confirmed by crosschecking them with online animal databases and relevant scientific literature. The study found 73 natural products belonging to 29 categories derived from 45 medicinal animals (36 vertebrates and 9 invertebrates), comprising of 9 taxonomic categories and 30 zoological families. Out of 116 formulations currently produced, 87 of them contain one or more extracts and products obtained from 13 medicinal animals to treat more than 124 traditionally classified illnesses. Only five animal ingredients were found available in Bhutan and rest of the animal parts are being imported from India. Out of 73 natural products described in the traditional textbooks, only 13 of them (some omitted and few substituted by plants) are currently included in 87 formulations of BSM. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Rescuing valuable genomes by animal cloning: a case for natural disease resistance in cattle.

PubMed

Westhusin, M E; Shin, T; Templeton, J W; Burghardt, R C; Adams, L G

2007-01-01

Tissue banking and animal cloning represent a powerful tool for conserving and regenerating valuable animal genomes. Here we report an example involving cattle and the rescue of a genome affording natural disease resistance. During the course of a 2-decade study involving the phenotypic and genotypic analysis for the functional and genetic basis of natural disease resistance against bovine brucellosis, a foundation sire was identified and confirmed to be genetically resistant to Brucella abortus. This unique animal was utilized extensively in numerous animal breeding studies to further characterize the genetic basis for natural disease resistance. The bull died in 1996 of natural causes, and no semen was available for AI, resulting in the loss of this valuable genome. Fibroblast cell lines had been established in 1985, cryopreserved, and stored in liquid nitrogen for future genetic analysis. Therefore, we decided to utilize these cells for somatic cell nuclear transfer to attempt the production of a cloned bull and salvage this valuable genotype. Embryos were produced by somatic cell nuclear transfer and transferred to 20 recipient cows, 10 of which became pregnant as determined by ultrasound at d 40 of gestation. One calf survived to term. At present, the cloned bull is 4.5 yr old and appears completely normal as determined by physical examination and blood chemistry. Furthermore, in vitro assays performed to date indicate this bull is naturally resistant to B. abortus, Mycobacterium bovis, and Salmonella typhimurium, as was the original genetic donor.

WordlePlus: Expanding Wordle's Use through Natural Interaction and Animation.

PubMed

Jo, Jaemin; Lee, Bongshin; Seo, Jinwook

2015-01-01

Wordle has been commonly used to summarize texts, with each word size-coded by its frequency of occurrences--the more often a word occurs in texts, the bigger it is. The interactive authoring tool WordlePlus leverages natural interaction and animation to give users more control over wordle development. WordlePlus supports direct manipulation of words with pen and touch interaction. It introduces two-word multitouch manipulation, such as concatenating and grouping two words, and provides pen interaction for adding and deleting words. In addition, WordlePlus employs animation to help users create more dynamic and engaging wordles.

Parallel shifts in ecology and natural selection in an island lizard

PubMed Central

Calsbeek, Ryan; Buermann, Wolfgang; Smith, Thomas B

2009-01-01

Background Natural selection is a potent evolutionary force that shapes phenotypic variation to match ecological conditions. However, we know little about the year-to-year consistency of selection, or how inter-annual variation in ecology shapes adaptive landscapes and ultimately adaptive radiations. Here we combine remote sensing data, field experiments, and a four-year study of natural selection to show that changes in vegetation structure associated with a severe drought altered both habitat use and natural selection in the brown anole, Anolis sagrei. Results In natural populations, lizards increased their use of vegetation in wet years and this was correlated with selection on limb length but not body size. By contrast, a die-back of vegetation caused by drought was followed by reduced arboreality, selection on body size, and relaxed selection on limb length. With the return of the rains and recovery of vegetation, selection reverted back to pre-drought pattern of selection acting on limb length but not body size. To test for the impact of vegetation loss on natural selection during the drought, we experimentally removed vegetation on a separate study island in a naturally wet year. The experiment revealed similar inter-annual changes in selection on body size but not limb length. Conclusion Our results illustrate the dynamic nature of ecology driving natural selection on Anolis morphology and emphasize the importance of inter-annual environmental variation in shaping adaptive variation. In addition, results illustrate the utility of using remote sensing data to examine ecology's role in driving natural selection. PMID:19126226

Bridging Emergent Attributes and Darwinian Principles in Teaching Natural Selection

ERIC Educational Resources Information Center

Xu, Dongchen; Chi, Michelene T. H.

2016-01-01

Students often have misconceptions about natural selection as they misuse a direct causal schema to explain the process. Natural selection is in fact an emergent process where random interactions lead to changes in a population. The misconceptions stem from students' lack of emergent schema for natural selection. In order to help students…

Using Card Games to Simulate the Process of Natural Selection

ERIC Educational Resources Information Center

Grilliot, Matthew E.; Harden, Siegfried

2014-01-01

In 1858, Darwin published "On the Origin of Species by Means of Natural Selection." His explanation of evolution by natural selection has become the unifying theme of biology. We have found that many students do not fully comprehend the process of evolution by natural selection. We discuss a few simple games that incorporate hands-on…

The 'Disadapted' Animal: Niko Tinbergen on Human Nature and the Human Predicament.

PubMed

Vicedo, Marga

2018-06-01

This paper explores ethologist Niko Tinbergen's path from animal to human studies in the 1960s and 1970s and his views about human nature. It argues, first, that the confluence of several factors explains why Tinbergen decided to cross the animal/human divide in the mid 1960s: his concern about what he called "the human predicament," his relations with British child psychiatrist John Bowlby, the success of ethological explanations of human behavior, and his professional and personal situation. It also argues that Tinbergen transferred his general adaptationist view of animal behavior to the realm of human biology; here, his concern about disadaptation led him to a view of human behavior that was strongly determined by the species' evolutionary past, a position that I call evolutionary determinism. These ideas can be seen in the work he carried out with his wife, Elisabeth Tinbergen, on autism. The paper concludes that Tinbergen's vision of human nature constitutes another version of what anthropologist Clifford Geertz called in 1966 the "stratigraphic" conception of the human: a view of human nature as a composite of levels in which a universal ancestral biological core is superimposed by psychological and cultural layers that represent accidental variation at best and pathological deviation at worst.

Hard and Soft Selection Revisited: How Evolution by Natural Selection Works in the Real World.

PubMed

Reznick, David

2016-01-01

The modern synthesis of evolutionary biology unified Darwin's natural selection with Mendelian genetics, but at the same time it created the dilemma of genetic load. Lewontin and Hubby's (1966) and Harris's (1966) characterization of genetic variation in natural populations increased the apparent burden of this load. Neutrality or near neutrality of genetic variation was one mechanism proposed for the revealed excessive genetic variation. Bruce Wallace coined the term "soft selection" to describe an alternative way for natural selection to operate that was consistent with observed variation. He envisioned nature as presenting ecological vacancies that could be filled by diverse genotypes. Survival and successful reproduction was a combined function of population density, genotype, and genotype frequencies, rather than a fixed value of the relative fitness of each genotype. My goal in this review is to explore the importance of soft selection in the real world. My motive and that of my colleagues as described here is not to explain what maintains genetic variation in natural populations, but rather to understand the factors that shape how organisms adapt to natural environments. We characterize how feedbacks between ecology and evolution shape both evolution and ecology. These feedbacks are mediated by density- and frequency-dependent selection, the mechanisms that underlie soft selection. Here, I report on our progress in characterizing these types of selection with a combination of a consideration of the published literature and the results from my collaborators' and my research on natural populations of guppies. © The American Genetic Association. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Genome Patterns of Selection and Introgression of Haplotypes in Natural Populations of the House Mouse (Mus musculus)

PubMed Central

Staubach, Fabian; Lorenc, Anna; Messer, Philipp W.; Tang, Kun; Petrov, Dmitri A.; Tautz, Diethard

2012-01-01

General parameters of selection, such as the frequency and strength of positive selection in natural populations or the role of introgression, are still insufficiently understood. The house mouse (Mus musculus) is a particularly well-suited model system to approach such questions, since it has a defined history of splits into subspecies and populations and since extensive genome information is available. We have used high-density single-nucleotide polymorphism (SNP) typing arrays to assess genomic patterns of positive selection and introgression of alleles in two natural populations of each of the subspecies M. m. domesticus and M. m. musculus. Applying different statistical procedures, we find a large number of regions subject to apparent selective sweeps, indicating frequent positive selection on rare alleles or novel mutations. Genes in the regions include well-studied imprinted loci (e.g. Plagl1/Zac1), homologues of human genes involved in adaptations (e.g. alpha-amylase genes) or in genetic diseases (e.g. Huntingtin and Parkin). Haplotype matching between the two subspecies reveals a large number of haplotypes that show patterns of introgression from specific populations of the respective other subspecies, with at least 10% of the genome being affected by partial or full introgression. Using neutral simulations for comparison, we find that the size and the fraction of introgressed haplotypes are not compatible with a pure migration or incomplete lineage sorting model. Hence, it appears that introgressed haplotypes can rise in frequency due to positive selection and thus can contribute to the adaptive genomic landscape of natural populations. Our data support the notion that natural genomes are subject to complex adaptive processes, including the introgression of haplotypes from other differentiated populations or species at a larger scale than previously assumed for animals. This implies that some of the admixture found in inbred strains of mice may also have

Six Classroom Exercises to Teach Natural Selection to Undergraduate Biology Students

PubMed Central

Kalinowski, Steven T.; Leonard, Mary J.; Andrews, Tessa M.; Litt, Andrea R.

2013-01-01

Students in introductory biology courses frequently have misconceptions regarding natural selection. In this paper, we describe six activities that biology instructors can use to teach undergraduate students in introductory biology courses how natural selection causes evolution. These activities begin with a lesson introducing students to natural selection and also include discussions on sexual selection, molecular evolution, evolution of complex traits, and the evolution of behavior. The set of six topics gives students the opportunity to see how natural selection operates in a variety of contexts. Pre- and postinstruction testing showed students’ understanding of natural selection increased substantially after completing this series of learning activities. Testing throughout this unit showed steadily increasing student understanding, and surveys indicated students enjoyed the activities. PMID:24006396

Natural Selection in a Petri Dish.

ERIC Educational Resources Information Center

McCarty, Robbie V.; Marek, Edmund A.

1997-01-01

Presents an activity to teach natural selection that involves students in a microbiological investigation. Students discover that a change in environmental conditions tests a species' range of adaptations. (DDR)

Cognitive Model of Animal Behavior to Comprehend an Aspect of Decision-Making

NASA Astrophysics Data System (ADS)

Migita, Masao; Moriyama, Tohru

2004-08-01

Most animal behaviors are considered to have been evolved through their own courses of natural selection. Since mechanisms of natural selection depend tightly on environments in which animals of interest inhabit, the environment for an animal appears a priori, and stimulus-response (S-R) relationships are stable as long as it returns constant benefit. We claim, however, no environment for an animal cannot be regarded as a priori and any animal can exhibit more elaborated behavior than S-R. In other words, every animal is more or less cognitive in terms that it may modify a meaning of stimulus. We introduce a minimal model to demonstrate the cognitive aspect of the pill bug's turn alternation (TA) behavior. The simulated pill bug can modify its own response pattern to the stimulus of water, though stable response appears to be prerequisite to TA behavior.

Just like the rest of evolution in Mother Nature, the evolution of cancers may be driven by natural selection, and not by haphazard mutations

PubMed Central

Zhang, Ju; Lou, Xiaomin; Zellmer, Lucas; Liu, Siqi; Xu, Ningzhi; Liao, D. Joshua

2014-01-01

Sporadic carcinogenesis starts from immortalization of a differentiated somatic cell or an organ-specific stem cell. The immortalized cell incepts a new or quasinew organism that lives like a parasite in the patient and usually proceeds to progressive simplification, constantly engendering intermediate organisms that are simpler than normal cells. Like organismal evolution in Mother Nature, this cellular simplification is a process of Darwinian selection of those mutations with growth- or survival-advantages, from numerous ones that occur randomly and stochastically. Therefore, functional gain of growth- or survival-sustaining oncogenes and functional loss of differentiation-sustaining tumor suppressor genes, which are hallmarks of cancer cells and contribute to phenotypes of greater malignancy, are not drivers of carcinogenesis but are results from natural selection of advantageous mutations. Besides this mutation-load dependent survival mechanism that is evolutionarily low and of an asexual nature, cancer cells may also use cell fusion for survival, which is an evolutionarily-higher mechanism and is of a sexual nature. Assigning oncogenes or tumor suppressor genes or their mutants as drivers to induce cancer in animals may somewhat coerce them to create man-made oncogenic pathways that may not really be a course of sporadic cancer formations in the human. PMID:25594068

Incorporating in situ habitat patchiness in site selection models reveals that site fidelity is not always a consequence of animal choice.

PubMed

Martinez, Aline S; Queiroz, Eduardo V; Bryson, Mitch; Byrne, Maria; Coleman, Ross A

2017-07-01

Understanding site fidelity is important in animal ecology, but evidence is lacking that this behaviour is due to an animal choosing a specific location. To discern site selection behaviour, it is necessary to consider the spatial distribution of habitats that animals can occupy within a landscape. Tracking animals and defining clear habitat boundaries, however, is often difficult. We use in situ habitat distribution data and animal movement simulations to investigate behavioural choice in site fidelity patterns. We resolved the difficulty of gathering data by working with intertidal rock pool systems, which are of manageable size and where boundaries are easy to define. Movements of the intertidal starfish Parvulastra exigua were quantified to test the hypotheses that (1) this species displays fidelity to a particular rock pool and that (2) rock pool fidelity is due to site selection behaviour. Observed patterns of individuals (n = 10 starfish) returning to a previously occupied rock pool (n = 5 pools per location) were tested against an expected null distribution generated through simulations of random movements within their natural patchy environment. Starfish exhibited site selection behaviour at only one location even though site fidelity was high (av. 7·4 starfish out of 10 found in test pools) in two of the three locations. The random chance of a starfish returning to a pool increased 67% for each metre further a rock pool was from the original pool, and 120% for each square metre increase in surface area of an original pool. The decision of returning to an original rock pool was influenced by food availability. When microalgal cover was >60%, there was a c. 50% chance of animals staying faithful to that pool. Our results show the importance to consider spatial distribution of habitats in understanding patterns of animal movement associated with animal choices and site fidelity. Returning to a particular place does not necessarily mean that an animal

Of Animals, Nature and People. Teacher's Guide. Preparing for Tomorrow's World.

ERIC Educational Resources Information Center

Iozzi, Louis A.; And Others

"Of Animals, Nature and People" is one of the "Preparing for Tomorrow's World" (PTW) program modules. PTW is an interdisciplinary, future-oriented program incorporating information from the sciences and social sciences and addressing societal concerns which interface science/technology/society. The program promotes responsible…

Genetic Selection to Enhance Animal Welfare Using Meat Inspection Data from Slaughter Plants

PubMed Central

Mathur, Pramod K.; Vogelzang, Roos; Mulder, Herman A.; Knol, Egbert F.

2018-01-01

Simple Summary Analysis of a large volume of meat inspection data suggests availability of genetic variation for most common indicators of poor animal welfare. This genetic variation can be used to select pigs that have the potential to resist common infections and other unfavorable welfare conditions. Genetic selection can be a tool in addition to farm management in reducing the risk of diseases, thereby reducing pain and suffering of animals. In general, the slaughter remarks have small but favorable genetic relationships with finishing and carcass quality traits. Therefore, it is possible to enhance animal welfare along with the genetic selection for economically important production traits. Abstract Animal health and welfare are monitored during meat inspection in many slaughter plants around the world. Carcasses are examined by meat inspectors and remarks are made with respect to different diseases, injuries, and other abnormalities. This is a valuable data resource for disease prevention and enhancing animal welfare, but it is rarely used for this purpose. Records on carcass remarks on 140,375 finisher pigs were analyzed to investigate the possibility of genetic selection to reduce the risk of the most prevalent diseases and indicators of suboptimal animal welfare. As part of this, effects of some non-genetic factors such as differences between farms, sexes, and growth rates were also examined. The most frequent remarks were pneumonia (15.4%), joint disorders (9.8%), pleuritis (4.7%), pericarditis (2.3%), and liver lesions (2.2%). Joint disorders were more frequent in boars than in gilts. There were also significant differences between farms. Pedigree records were available for 142,324 pigs from 14 farms and were used for genetic analysis. Heritability estimates for pneumonia, pleuritis, pericarditis, liver lesions, and joint disorders were 0.10, 0.09, 0.14, 0.24, and 0.17 on the liability scale, respectively, suggesting the existence of substantial genetic

Selections that isolate recombinant mitochondrial genomes in animals

PubMed Central

Ma, Hansong; O'Farrell, Patrick H

2015-01-01

Homologous recombination is widespread and catalyzes evolution. Nonetheless, its existence in animal mitochondrial DNA is questioned. We designed selections for recombination between co-resident mitochondrial genomes in various heteroplasmic Drosophila lines. In four experimental settings, recombinant genomes became the sole or dominant genome in the progeny. Thus, selection uncovers occurrence of homologous recombination in Drosophila mtDNA and documents its functional benefit. Double-strand breaks enhanced recombination in the germline and revealed somatic recombination. When the recombination partner was a diverged Drosophila melanogaster genome or a genome from a different species such as Drosophila yakuba, sequencing revealed long continuous stretches of exchange. In addition, the distribution of sequence polymorphisms in recombinants allowed us to map a selected trait to a particular region in the Drosophila mitochondrial genome. Thus, recombination can be harnessed to dissect function and evolution of mitochondrial genome. DOI: http://dx.doi.org/10.7554/eLife.07247.001 PMID:26237110

Equivalence between Step Selection Functions and Biased Correlated Random Walks for Statistical Inference on Animal Movement.

PubMed

Duchesne, Thierry; Fortin, Daniel; Rivest, Louis-Paul

2015-01-01

Animal movement has a fundamental impact on population and community structure and dynamics. Biased correlated random walks (BCRW) and step selection functions (SSF) are commonly used to study movements. Because no studies have contrasted the parameters and the statistical properties of their estimators for models constructed under these two Lagrangian approaches, it remains unclear whether or not they allow for similar inference. First, we used the Weak Law of Large Numbers to demonstrate that the log-likelihood function for estimating the parameters of BCRW models can be approximated by the log-likelihood of SSFs. Second, we illustrated the link between the two approaches by fitting BCRW with maximum likelihood and with SSF to simulated movement data in virtual environments and to the trajectory of bison (Bison bison L.) trails in natural landscapes. Using simulated and empirical data, we found that the parameters of a BCRW estimated directly from maximum likelihood and by fitting an SSF were remarkably similar. Movement analysis is increasingly used as a tool for understanding the influence of landscape properties on animal distribution. In the rapidly developing field of movement ecology, management and conservation biologists must decide which method they should implement to accurately assess the determinants of animal movement. We showed that BCRW and SSF can provide similar insights into the environmental features influencing animal movements. Both techniques have advantages. BCRW has already been extended to allow for multi-state modeling. Unlike BCRW, however, SSF can be estimated using most statistical packages, it can simultaneously evaluate habitat selection and movement biases, and can easily integrate a large number of movement taxes at multiple scales. SSF thus offers a simple, yet effective, statistical technique to identify movement taxis.

Natural habitats matter: Determinants of spatial pattern in the composition of animal assemblages of the Czech Republic

NASA Astrophysics Data System (ADS)

Divíšek, Jan; Zelený, David; Culek, Martin; Št'astný, Karel

2014-08-01

Studies that explore species-environment relationships at a broad scale are usually limited by the availability of sufficient habitat description, which is often too coarse to differentiate natural habitat patches. Therefore, it is not well understood how the distribution of natural habitats affects broad-scale patterns in the distribution of animal species. In this study, we evaluate the role of field-mapped natural habitats, land-cover types derived from remote sensing and climate on the composition of assemblages of five distinct animal groups, namely non-volant mammals, birds, reptiles, amphibians and butterflies native to the Czech Republic. First, we used variation partitioning based on redundancy analysis to evaluate the extent to which the environmental variables and their spatial structure might underlie the observed spatial patterns in the composition of animal assemblages. Second, we partitioned variations explained by climate, natural habitats and land-cover to compare their relative importance. Finally, we tested the independent effects of each variable in order to evaluate the significance of their contributions to the environmental model. Our results showed that spatial patterns in the composition of assemblages of almost all the considered animal groups may be ascribed mostly to variations in the environment. Although the shared effects of climatic variables, natural habitats and land-cover types explained the largest proportion of variation in each animal group, the variation explained purely by natural habitats was always higher than the variation explained purely by climate or land-cover. We conclude that most spatial variation in the composition of assemblages of almost all animal groups probably arises from biological processes operating within a spatially structured environment and suggest that natural habitats are important to explain observed patterns because they often perform better than habitat descriptions based on remote sensing. This

Environmental Status of the Lake Michigan Region Volume 11. Natural Areas of the Lake Michigan Drainage Basin and Endangered or Threatened Plant and Animal Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stearns, Forest; Lindsley, Diane

1977-09-01

The accelerating encroachment of human activity on the natural landscape has made many citizens appreciate the need to save representative biotic communities before urbanization and technologically induced change eliminate such communities. Active programs in natural-area preservation a.re now in progress in the four basin states; these programs have strong public support and legislative mandate. Local, state, and federal agencies and private individuals have taken an active interest in protecting select areas as samples of the biotic communities and natural features of the Basin. Most natural areas described in this report have been dedicated or reserved in some fashion. Other areasmore » are being added by the basin states each year. The maintenance of natural communities is closely linked to the preservation of endangered and threatened species of plants and animals which would cease to survive as isolated populations. Under federal regulations, certain plants and animals are listed as endange~ ed or threatened in the Basin. As individual state lists are prepared and investigations proceed, it is probable that many more threatened species will be found.« less

Environmental status of the Lake Michigan region. Volume II. Natural areas of the Lake Michigan drainage basin and endangered or threatened plant and animal species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stearns, F.; Lindsley, D.

1977-09-01

The accelerating encroachment of human activity on the natural landscape has made many citizens appreciate the need to save representative biotic communities before urbanization and technologically induced change eliminate such communities. Active programs in natural-area preservation are now in progress in the four basin states; these programs have strong public support and legislative mandate. Local, state, and federal agencies and private individuals have taken an active interest in protecting select areas as samples of the biotic communities and natural features of the Basin. Most natural areas described in this report have been dedicated or reserved in some fashion. Other areasmore » are being added by the basin states each year. The maintenance of natural communities is closely linked to the preservation of endangered and threatened species of plants and animals which would cease to survive as isolated populations. Under federal regulations, certain plants and animals are listed as endangered or threatened in the Basin. As individual state lists are prepared and investigations proceed, it is probable that many more threatened species will be found.« less

Concurrent natural and sexual selection in wild male sockeye salmon, Oncorhynchus nerka.

PubMed

Hamon, Troy R; Foote, Chris J

2005-05-01

Concurrent natural and sexual selection have been inferred from laboratory and comparative studies in a number of taxa, but are rarely measured in natural populations. Because the interaction of these two general categories of selection may be complex when they occur simultaneously, empirical evidence from natural populations would help us to understand this interaction and probably give us greater insight into each separate episode as well. In male sockeye salmon, sexual selection for larger body size has been indicated in both deep and shallow water habitats. However, in shallow habitats male sockeye are generally smaller and less deep-bodied than in deep habitats, a difference that has been ascribed to natural selection. We measured concurrent natural and sexual selection in two years on breeding male sockeye salmon with respect to body size, body shape, and time of arrival to the breeding grounds. Natural selection was variable in effect and sexual selection was variable in intensity in these two years. The patterns of selection also appear to be interdependent; areas where predation on spawning adults is not intense have yielded different patterns of sexual selection than those measured here. It appears that some of the body shape differences in sockeye salmon associated with different spawning habitats, which were previously attributed to selective mortality, may be a result of different patterns of sexual selection in the different habitats. Total selection resulting from the combination of both natural and sexual selection was less intense than either natural or sexual selection in most cases. Measurement of concurrent selection episodes in nature may help us to understand whether the pattern of differential sexual selection is common, and whether observed patterns of habitat-related differentiation may be due to differences in sexual selection.

Human-induced evolution caused by unnatural selection through harvest of wild animals

PubMed Central

Allendorf, Fred W.; Hard, Jeffrey J.

2009-01-01

Human harvest of phenotypically desirable animals from wild populations imposes selection that can reduce the frequencies of those desirable phenotypes. Hunting and fishing contrast with agricultural and aquacultural practices in which the most desirable animals are typically bred with the specific goal of increasing the frequency of desirable phenotypes. We consider the potential effects of harvest on the genetics and sustainability of wild populations. We also consider how harvesting could affect the mating system and thereby modify sexual selection in a way that might affect recruitment. Determining whether phenotypic changes in harvested populations are due to evolution, rather than phenotypic plasticity or environmental variation, has been problematic. Nevertheless, it is likely that some undesirable changes observed over time in exploited populations (e.g., reduced body size, earlier sexual maturity, reduced antler size, etc.) are due to selection against desirable phenotypes—a process we call “unnatural” selection. Evolution brought about by human harvest might greatly increase the time required for over-harvested populations to recover once harvest is curtailed because harvesting often creates strong selection differentials, whereas curtailing harvest will often result in less intense selection in the opposing direction. We strongly encourage those responsible for managing harvested wild populations to take into account possible selective effects of harvest management and to implement monitoring programs to detect exploitation-induced selection before it seriously impacts viability. PMID:19528656

A Gambler's Model of Natural Selection.

ERIC Educational Resources Information Center

Nolan, Michael J.; Ostrovsky, David S.

1996-01-01

Presents an activity that highlights the mechanism and power of natural selection. Allows students to think in terms of modeling a biological process and instills an appreciation for a mathematical approach to biological problems. (JRH)

Development and Validation of the Conceptual Assessment of Natural Selection (CANS)

ERIC Educational Resources Information Center

Kalinowski, Steven T.; Leonard, Mary J.; Taper, Mark L.

2016-01-01

We developed and validated the Conceptual Assessment of Natural Selection (CANS), a multiple-choice test designed to assess how well college students understand the central principles of natural selection. The expert panel that reviewed the CANS concluded its questions were relevant to natural selection and generally did a good job sampling the…

More than Meets the Eye--a Simulation of Natural Selection.

ERIC Educational Resources Information Center

Allen, J. A.; And Others

1987-01-01

Presents experiments using wild birds as predators and pastry as prey and colored stones as background to demonstrate natural selection. Describes the exercise as an exercise in simulating natural selection. (Author/CW)

Development and Validation of the Conceptual Assessment of Natural Selection (CANS)

PubMed Central

Kalinowski, Steven T.; Leonard, Mary J.; Taper, Mark L.

2016-01-01

We developed and validated the Conceptual Assessment of Natural Selection (CANS), a multiple-choice test designed to assess how well college students understand the central principles of natural selection. The expert panel that reviewed the CANS concluded its questions were relevant to natural selection and generally did a good job sampling the specific concepts they were intended to assess. Student interviews confirmed questions on the CANS provided accurate reflections of how students think about natural selection. And, finally, statistical analysis of student responses using item response theory showed that the CANS did a very good job of estimating how well students understood natural selection. The empirical reliability of the CANS was substantially higher than the Force Concept Inventory, a highly regarded test in physics that has a similar purpose. PMID:27856552

Missing concepts in natural selection theory reconstructions.

PubMed

Ginnobili, Santiago

2016-09-01

The concept of fitness has generated a lot of discussion in philosophy of biology. There is, however, relative agreement about the need to distinguish at least two uses of the term: ecological fitness on the one hand, and population genetics fitness on the other. The goal of this paper is to give an explication of the concept of ecological fitness by providing a reconstruction of the theory of natural selection in which this concept was framed, that is, based on the way the theory was put to use in Darwin's main texts. I will contend that this reconstruction enables us to account for the current use of the theory of natural selection. The framework presupposed in the analysis will be that of metatheoretical structuralism. This framework will provide both a better understanding of the nature of ecological fitness and a more complete reconstruction of the theory. In particular, it will provide what I think is a better way of understanding how the concept of fitness is applied through heterogeneous cases. One of the major advantages of my way of thinking about natural selection theory is that it would not have the peculiar metatheoretical status that it has in other available views. I will argue that in order to achieve these goals it is necessary to make several concepts explicit, concepts that are frequently omitted in usual reconstructions.

The insufficient part of abiogenesis theory - natural selection

NASA Astrophysics Data System (ADS)

Ploompuu, Tõnu

2016-04-01

Abiogenesis has already been studied for a whole century. There have been studies on the synthesis of precursors of biopolymers, concentration processes and polymerization pathways, sites of initiation of life. Autoreplication has been explained. Protocells have been constructed from abiogenic membranes. But one essential aspect for life - the natural selection - has been marginalized in these investigations. Despite the convincing use of natural selection in biology for one and half century, it has not been used sufficiently in the models of the beginning of life. Pictorially - Darwin's pond model is used without darwinism. This generates an unnecessary interruption on the path for understanding the process. Natural selection is essential in abiogenesis, in the genesis of biological information system. A selection of more collaborative autoreplicate biopolymers and the depolymerisation of others was required. Only natural selection was able to combine biopolymer molecules for life. The primary natural selection can operate only in an environment with variable physical and chemical conditions. The selective agent must constantly fluctuate during a long time span and a large area. Formation of the simplest complex of life needs homeostasis. The best sites for constant fluctuations are littoral areas of oceans. Two very constant fluctuations - waves and tides - occur there. The best conditions for the origin of life were exactly in the end of the Late Heavy Bombardment at temperature nealy 100° C. Earth's surface was then protected against the UV destruction by a thick cloud cover. High evaporation at the hotter parts of shore rocks increased the concentration of the primordial soup and there was excellent selective power by routine water level fluctuations. Because of the water level fluctuations salty ocean water and fresh water from continuous downpours alternated at the littoral zones. In low temperatures the formation of life would be hindered by UV

Microbial Resistance to Triclosan: A Case Study in Natural Selection

ERIC Educational Resources Information Center

Serafini, Amanda; Matthews, Dorothy M.

2009-01-01

Natural selection is the mechanism of evolution caused by the environmental selection of organisms most fit to reproduce, sometimes explained as "survival of the fittest." An example of evolution by natural selection is the development of bacteria that are resistant to antimicrobial agents as a result of exposure to these agents. Triclosan, which…

From wild animals to domestic pets, an evolutionary view of domestication.

PubMed

Driscoll, Carlos A; Macdonald, David W; O'Brien, Stephen J

2009-06-16

Artificial selection is the selection of advantageous natural variation for human ends and is the mechanism by which most domestic species evolved. Most domesticates have their origin in one of a few historic centers of domestication as farm animals. Two notable exceptions are cats and dogs. Wolf domestication was initiated late in the Mesolithic when humans were nomadic hunter-gatherers. Those wolves less afraid of humans scavenged nomadic hunting camps and over time developed utility, initially as guards warning of approaching animals or other nomadic bands and soon thereafter as hunters, an attribute tuned by artificial selection. The first domestic cats had limited utility and initiated their domestication among the earliest agricultural Neolithic settlements in the Near East. Wildcat domestication occurred through a self-selective process in which behavioral reproductive isolation evolved as a correlated character of assortative mating coupled to habitat choice for urban environments. Eurasian wildcats initiated domestication and their evolution to companion animals was initially a process of natural, rather than artificial, selection over time driven during their sympatry with forbear wildcats.

Natural selection and inheritance of breeding time and clutch size in the collared flycatcher.

PubMed

Sheldon, B C; Kruuk, L E B; Merilä, J

2003-02-01

Many characteristics of organisms in free-living populations appear to be under directional selection, possess additive genetic variance, and yet show no evolutionary response to selection. Avian breeding time and clutch size are often-cited examples of such characters. We report analyses of inheritance of, and selection on, these traits in a long-term study of a wild population of the collared flycatcher Ficedula albicollis. We used mixed model analysis with REML estimation ("animal models") to make full use of the information in complex multigenerational pedigrees. Heritability of laying date, but not clutch size, was lower than that estimated previously using parent-offspring regressions, although for both traits there was evidence of substantial additive genetic variance (h2 = 0.19 and 0.29, respectively). Laying date and clutch size were negatively genetically correlated (rA = -0.41 +/- 0.09), implying that selection on one of the traits would cause a correlated response in the other, but there was little evidence to suggest that evolution of either trait would be constrained by correlations with other phenotypic characters. Analysis of selection on these traits in females revealed consistent strong directional fecundity selection for earlier breeding at the level of the phenotype (beta = -0.28 +/- 0.03), but little evidence for stabilising selection on breeding time. We found no evidence that clutch size was independently under selection. Analysis of fecundity selection on breeding values for laying date, estimated from an animal model, indicated that selection acts directly on additive genetic variance underlying breeding time (beta = -0.20 +/- 0.04), but not on clutch size (beta = 0.03 +/- 0.05). In contrast, selection on laying date via adult female survival fluctuated in sign between years, and was opposite in sign for selection on phenotypes (negative) and breeding values (positive). Our data thus suggest that any evolutionary response to selection on

Using David Lack's Observations of Finch Beak Size to Teach Natural Selection & the Nature of Science

ERIC Educational Resources Information Center

Bierema, Andrea M.-K.; Rudge, David W.

2014-01-01

One of the key aspects of natural selection is competition, yet the concept of competition is not necessarily emphasized in explanations of natural selection. Because of this, we developed an activity for our class that focuses on competition and provides an example of the effects of competition on natural selection. This hands-on activity models…

Can we use genetic and genomic approaches to identify candidate animals for targeted selective treatment.

PubMed

Laurenson, Yan C S M; Kyriazakis, Ilias; Bishop, Stephen C

2013-10-18

Estimated breeding values (EBV) for faecal egg count (FEC) and genetic markers for host resistance to nematodes may be used to identify resistant animals for selective breeding programmes. Similarly, targeted selective treatment (TST) requires the ability to identify the animals that will benefit most from anthelmintic treatment. A mathematical model was used to combine the concepts and evaluate the potential of using genetic-based methods to identify animals for a TST regime. EBVs obtained by genomic prediction were predicted to be the best determinant criterion for TST in terms of the impact on average empty body weight and average FEC, whereas pedigree-based EBVs for FEC were predicted to be marginally worse than using phenotypic FEC as a determinant criterion. Whilst each method has financial implications, if the identification of host resistance is incorporated into a wider genomic selection indices or selective breeding programmes, then genetic or genomic information may be plausibly included in TST regimes. Copyright © 2013 Elsevier B.V. All rights reserved.

Supranormal orientation selectivity of visual neurons in orientation-restricted animals.

PubMed

Sasaki, Kota S; Kimura, Rui; Ninomiya, Taihei; Tabuchi, Yuka; Tanaka, Hiroki; Fukui, Masayuki; Asada, Yusuke C; Arai, Toshiya; Inagaki, Mikio; Nakazono, Takayuki; Baba, Mika; Kato, Daisuke; Nishimoto, Shinji; Sanada, Takahisa M; Tani, Toshiki; Imamura, Kazuyuki; Tanaka, Shigeru; Ohzawa, Izumi

2015-11-16

Altered sensory experience in early life often leads to remarkable adaptations so that humans and animals can make the best use of the available information in a particular environment. By restricting visual input to a limited range of orientations in young animals, this investigation shows that stimulus selectivity, e.g., the sharpness of tuning of single neurons in the primary visual cortex, is modified to match a particular environment. Specifically, neurons tuned to an experienced orientation in orientation-restricted animals show sharper orientation tuning than neurons in normal animals, whereas the opposite was true for neurons tuned to non-experienced orientations. This sharpened tuning appears to be due to elongated receptive fields. Our results demonstrate that restricted sensory experiences can sculpt the supranormal functions of single neurons tailored for a particular environment. The above findings, in addition to the minimal population response to orientations close to the experienced one, agree with the predictions of a sparse coding hypothesis in which information is represented efficiently by a small number of activated neurons. This suggests that early brain areas adopt an efficient strategy for coding information even when animals are raised in a severely limited visual environment where sensory inputs have an unnatural statistical structure.

Supranormal orientation selectivity of visual neurons in orientation-restricted animals

PubMed Central

Sasaki, Kota S.; Kimura, Rui; Ninomiya, Taihei; Tabuchi, Yuka; Tanaka, Hiroki; Fukui, Masayuki; Asada, Yusuke C.; Arai, Toshiya; Inagaki, Mikio; Nakazono, Takayuki; Baba, Mika; Kato, Daisuke; Nishimoto, Shinji; Sanada, Takahisa M.; Tani, Toshiki; Imamura, Kazuyuki; Tanaka, Shigeru; Ohzawa, Izumi

2015-01-01

Altered sensory experience in early life often leads to remarkable adaptations so that humans and animals can make the best use of the available information in a particular environment. By restricting visual input to a limited range of orientations in young animals, this investigation shows that stimulus selectivity, e.g., the sharpness of tuning of single neurons in the primary visual cortex, is modified to match a particular environment. Specifically, neurons tuned to an experienced orientation in orientation-restricted animals show sharper orientation tuning than neurons in normal animals, whereas the opposite was true for neurons tuned to non-experienced orientations. This sharpened tuning appears to be due to elongated receptive fields. Our results demonstrate that restricted sensory experiences can sculpt the supranormal functions of single neurons tailored for a particular environment. The above findings, in addition to the minimal population response to orientations close to the experienced one, agree with the predictions of a sparse coding hypothesis in which information is represented efficiently by a small number of activated neurons. This suggests that early brain areas adopt an efficient strategy for coding information even when animals are raised in a severely limited visual environment where sensory inputs have an unnatural statistical structure. PMID:26567927

Sound imaging of nocturnal animal calls in their natural habitat.

PubMed

Mizumoto, Takeshi; Aihara, Ikkyu; Otsuka, Takuma; Takeda, Ryu; Aihara, Kazuyuki; Okuno, Hiroshi G

2011-09-01

We present a novel method for imaging acoustic communication between nocturnal animals. Investigating the spatio-temporal calling behavior of nocturnal animals, e.g., frogs and crickets, has been difficult because of the need to distinguish many animals' calls in noisy environments without being able to see them. Our method visualizes the spatial and temporal dynamics using dozens of sound-to-light conversion devices (called "Firefly") and an off-the-shelf video camera. The Firefly, which consists of a microphone and a light emitting diode, emits light when it captures nearby sound. Deploying dozens of Fireflies in a target area, we record calls of multiple individuals through the video camera. We conduct two experiments, one indoors and the other in the field, using Japanese tree frogs (Hyla japonica). The indoor experiment demonstrates that our method correctly visualizes Japanese tree frogs' calling behavior. It has confirmed the known behavior; two frogs call synchronously or in anti-phase synchronization. The field experiment (in a rice paddy where Japanese tree frogs live) also visualizes the same calling behavior to confirm anti-phase synchronization in the field. Experimental results confirm that our method can visualize the calling behavior of nocturnal animals in their natural habitat.

[Live Animals and Staged Nature : Drawing and Photography in German Popular Zoology between 1860 and 1910].

PubMed

Gall, Alexander

2017-06-01

It is the central thesis of this paper that the "biological perspective" (Lynn Nyhart) typical for Germany, with its interest in living animals, not only influenced natural history practices in many ways during the second half of the 19th century, rather also shaped the illustrations of popular zoology publications, as for example those in Brehms Thierleben. The illustrators of this period preferred to use live animals as models, which they studied in zoos. These animals were often depicted in their "natural" habitats. Since the illustrators knew only very little about these habitats, they had to be imagined. Another fashionable genre within popular zoology was the portrayal of animals fighting, which attracted attention because of their drama. The first wildlife photographers oriented themselves on the zoological illustrations and, with the aid of manipulation, staging and retouching, gave their photographs the impression of natural surroundings and drama. Yet both the illustrators and the photographers emphasized their truth to nature and - based on this - the scientific value of their pictures. In so doing, they developed a "biological" kind of wildlife photography, which, after the turn of the 19th century, allowed dedicated amateurs to create a popular zoological oeuvre that was well received by broad audiences.

The genetic consequences of selection in natural populations.

PubMed

Thurman, Timothy J; Barrett, Rowan D H

2016-04-01

The selection coefficient, s, quantifies the strength of selection acting on a genetic variant. Despite this parameter's central importance to population genetic models, until recently we have known relatively little about the value of s in natural populations. With the development of molecular genetic techniques in the late 20th century and the sequencing technologies that followed, biologists are now able to identify genetic variants and directly relate them to organismal fitness. We reviewed the literature for published estimates of natural selection acting at the genetic level and found over 3000 estimates of selection coefficients from 79 studies. Selection coefficients were roughly exponentially distributed, suggesting that the impact of selection at the genetic level is generally weak but can occasionally be quite strong. We used both nonparametric statistics and formal random-effects meta-analysis to determine how selection varies across biological and methodological categories. Selection was stronger when measured over shorter timescales, with the mean magnitude of s greatest for studies that measured selection within a single generation. Our analyses found conflicting trends when considering how selection varies with the genetic scale (e.g., SNPs or haplotypes) at which it is measured, suggesting a need for further research. Besides these quantitative conclusions, we highlight key issues in the calculation, interpretation, and reporting of selection coefficients and provide recommendations for future research. © 2016 John Wiley & Sons Ltd.

Of Animals, Nature and People. [Student's Guide.] Preparing for Tomorrow's World.

ERIC Educational Resources Information Center

Iozzi, Louis A.; And Others

Developing an awareness of the need to evolve an environmental ethic is the intent of this module, designed for the senior high school level (grades 10-11). The module is divided into two sections. Section 1 contains a series of dilemma/discussion activities raising issues regarding human behavior toward animals and the natural environment.…

Animation of natural scene by virtual eye-movements evokes high precision and low noise in V1 neurons

PubMed Central

Baudot, Pierre; Levy, Manuel; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

2013-01-01

Synaptic noise is thought to be a limiting factor for computational efficiency in the brain. In visual cortex (V1), ongoing activity is present in vivo, and spiking responses to simple stimuli are highly unreliable across trials. Stimulus statistics used to plot receptive fields, however, are quite different from those experienced during natural visuomotor exploration. We recorded V1 neurons intracellularly in the anaesthetized and paralyzed cat and compared their spiking and synaptic responses to full field natural images animated by simulated eye-movements to those evoked by simpler (grating) or higher dimensionality statistics (dense noise). In most cells, natural scene animation was the only condition where high temporal precision (in the 10–20 ms range) was maintained during sparse and reliable activity. At the subthreshold level, irregular but highly reproducible membrane potential dynamics were observed, even during long (several 100 ms) “spike-less” periods. We showed that both the spatial structure of natural scenes and the temporal dynamics of eye-movements increase the signal-to-noise ratio by a non-linear amplification of the signal combined with a reduction of the subthreshold contextual noise. These data support the view that the sparsening and the time precision of the neural code in V1 may depend primarily on three factors: (1) broadband input spectrum: the bandwidth must be rich enough for recruiting optimally the diversity of spatial and time constants during recurrent processing; (2) tight temporal interplay of excitation and inhibition: conductance measurements demonstrate that natural scene statistics narrow selectively the duration of the spiking opportunity window during which the balance between excitation and inhibition changes transiently and reversibly; (3) signal energy in the lower frequency band: a minimal level of power is needed below 10 Hz to reach consistently the spiking threshold, a situation rarely reached with visual

Animation of natural scene by virtual eye-movements evokes high precision and low noise in V1 neurons.

PubMed

Baudot, Pierre; Levy, Manuel; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

2013-01-01

Synaptic noise is thought to be a limiting factor for computational efficiency in the brain. In visual cortex (V1), ongoing activity is present in vivo, and spiking responses to simple stimuli are highly unreliable across trials. Stimulus statistics used to plot receptive fields, however, are quite different from those experienced during natural visuomotor exploration. We recorded V1 neurons intracellularly in the anaesthetized and paralyzed cat and compared their spiking and synaptic responses to full field natural images animated by simulated eye-movements to those evoked by simpler (grating) or higher dimensionality statistics (dense noise). In most cells, natural scene animation was the only condition where high temporal precision (in the 10-20 ms range) was maintained during sparse and reliable activity. At the subthreshold level, irregular but highly reproducible membrane potential dynamics were observed, even during long (several 100 ms) "spike-less" periods. We showed that both the spatial structure of natural scenes and the temporal dynamics of eye-movements increase the signal-to-noise ratio by a non-linear amplification of the signal combined with a reduction of the subthreshold contextual noise. These data support the view that the sparsening and the time precision of the neural code in V1 may depend primarily on three factors: (1) broadband input spectrum: the bandwidth must be rich enough for recruiting optimally the diversity of spatial and time constants during recurrent processing; (2) tight temporal interplay of excitation and inhibition: conductance measurements demonstrate that natural scene statistics narrow selectively the duration of the spiking opportunity window during which the balance between excitation and inhibition changes transiently and reversibly; (3) signal energy in the lower frequency band: a minimal level of power is needed below 10 Hz to reach consistently the spiking threshold, a situation rarely reached with visual dense

Study of dung, urine, and milk of selected grazing animals as bioindicators in environmental geoscience--a case study from Mangampeta barite mining area, Kadapa District, Andhra Pradesh, India.

PubMed

Raghu, V

2015-01-01

The ancient scientific Sanskrit texts of Ayurveda (science of longevity) deal with waters, plants, and animals in relation to human health. Based on the studies mentioned in Ayurveda and modern literature, biological responses of grazing animals in Mangampeta barite mining area in Kadapa District, Andhra Pradesh, were studied. A non-mineralized Tirupati area in Chittoor District, Andhra Pradesh, was selected for the purpose of comparison. In these areas, certain animal products of selected grazing animals were studied if they could be used as tools in mineral exploration. Samples of dung, urine, and milk from cow, bullock, she-buffalo, he-buffalo, sheep, and goat were collected from these two areas during winter and summer seasons. Goat dung was found to have lowest moisture content and highest organic matter while goat urine contained highest amounts of organic matter and ash content. All these animal products were analyzed for 11 trace elements. The concentration of trace elements released through dung, urine, and milk widely varied in different animal species with seasonal variations. The elemental concentration was higher in dung and lower in urine, when compared to that of milk. The concentration of all elements in dung, urine, and milk of all animals, in both the areas, was higher in winter than that in summer. Dung represents the metabolic process of the whole animal and reflects the dietary conditions whether fed on natural or inorganic supplement. It can be inferred that dung, urine, and milk of any animal can be used as tools in mineral exploration during winter, while during summer, only dung can be useful. The dung of goat when compared to that of the other cattle serves as a better tool in environmental studies as goat depends almost entirely on natural vegetation without human interference.

Application of random effects to the study of resource selection by animals

USGS Publications Warehouse

Gillies, C.S.; Hebblewhite, M.; Nielsen, S.E.; Krawchuk, M.A.; Aldridge, Cameron L.; Frair, J.L.; Saher, D.J.; Stevens, C.E.; Jerde, C.L.

2006-01-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence.2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability.3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed.4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects.5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection.6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions

Application of random effects to the study of resource selection by animals.

PubMed

Gillies, Cameron S; Hebblewhite, Mark; Nielsen, Scott E; Krawchuk, Meg A; Aldridge, Cameron L; Frair, Jacqueline L; Saher, D Joanne; Stevens, Cameron E; Jerde, Christopher L

2006-07-01

1. Resource selection estimated by logistic regression is used increasingly in studies to identify critical resources for animal populations and to predict species occurrence. 2. Most frequently, individual animals are monitored and pooled to estimate population-level effects without regard to group or individual-level variation. Pooling assumes that both observations and their errors are independent, and resource selection is constant given individual variation in resource availability. 3. Although researchers have identified ways to minimize autocorrelation, variation between individuals caused by differences in selection or available resources, including functional responses in resource selection, have not been well addressed. 4. Here we review random-effects models and their application to resource selection modelling to overcome these common limitations. We present a simple case study of an analysis of resource selection by grizzly bears in the foothills of the Canadian Rocky Mountains with and without random effects. 5. Both categorical and continuous variables in the grizzly bear model differed in interpretation, both in statistical significance and coefficient sign, depending on how a random effect was included. We used a simulation approach to clarify the application of random effects under three common situations for telemetry studies: (a) discrepancies in sample sizes among individuals; (b) differences among individuals in selection where availability is constant; and (c) differences in availability with and without a functional response in resource selection. 6. We found that random intercepts accounted for unbalanced sample designs, and models with random intercepts and coefficients improved model fit given the variation in selection among individuals and functional responses in selection. Our empirical example and simulations demonstrate how including random effects in resource selection models can aid interpretation and address difficult assumptions

A Raven in a Coal Scuttle: Theodore Roosevelt & the Animal Coloration Controversy.

ERIC Educational Resources Information Center

Hendrick, Robert

1995-01-01

Recounts a debate between Theodore Roosevelt and Abbott Thayer in 1909-12 over whether animal coloration was an adaptation resulting from natural selection or whether the animal's environment acted directly on it to form its color patterns. (ZWH)

Getting to Darwin: Obstacles to Accepting Evolution by Natural Selection

ERIC Educational Resources Information Center

Thagard, Paul; Findlay, Scott

2010-01-01

Darwin's theory of evolution by natural selection is central to modern biology, but is resisted by many people. This paper discusses the major psychological obstacles to accepting Darwin's theory. Cognitive obstacles to adopting evolution by natural selection include conceptual difficulties, methodological issues, and coherence problems that…

Simulating natural selection in landscape genetics

Treesearch

E. L. Landguth; S. A. Cushman; N. Johnson

2012-01-01

Linking landscape effects to key evolutionary processes through individual organism movement and natural selection is essential to provide a foundation for evolutionary landscape genetics. Of particular importance is determining how spatially- explicit, individual-based models differ from classic population genetics and evolutionary ecology models based on ideal...

Natural Selection in Large Populations

NASA Astrophysics Data System (ADS)

Desai, Michael

2011-03-01

I will discuss theoretical and experimental approaches to the evolutionary dynamics and population genetics of natural selection in large populations. In these populations, many mutations are often present simultaneously, and because recombination is limited, selection cannot act on them all independently. Rather, it can only affect whole combinations of mutations linked together on the same chromosome. Methods common in theoretical population genetics have been of limited utility in analyzing this coupling between the fates of different mutations. In the past few years it has become increasingly clear that this is a crucial gap in our understanding, as sequence data has begun to show that selection appears to act pervasively on many linked sites in a wide range of populations, including viruses, microbes, Drosophila, and humans. I will describe approaches that combine analytical tools drawn from statistical physics and dynamical systems with traditional methods in theoretical population genetics to address this problem, and describe how experiments in budding yeast can help us directly observe these evolutionary dynamics.

Natural and sexual selection in a monogamous historical human population.

PubMed

Courtiol, Alexandre; Pettay, Jenni E; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

2012-05-22

Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760-1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species.

Natural and sexual selection in a monogamous historical human population

PubMed Central

Courtiol, Alexandre; Pettay, Jenni E.; Jokela, Markus; Rotkirch, Anna; Lummaa, Virpi

2012-01-01

Whether and how human populations exposed to the agricultural revolution are still affected by Darwinian selection remains controversial among social scientists, biologists, and the general public. Although methods of studying selection in natural populations are well established, our understanding of selection in humans has been limited by the availability of suitable datasets. Here, we present a study comparing the maximum strengths of natural and sexual selection in humans that includes the effects of sex and wealth on different episodes of selection. Our dataset was compiled from church records of preindustrial Finnish populations characterized by socially imposed monogamy, and it contains a complete distribution of survival, mating, and reproductive success for 5,923 individuals born 1760–1849. Individual differences in early survival and fertility (natural selection) were responsible for most variation in fitness, even among wealthier individuals. Variance in mating success explained most of the higher variance in reproductive success in males compared with females, but mating success also influenced reproductive success in females, allowing for sexual selection to operate in both sexes. The detected opportunity for selection is in line with measurements for other species but higher than most previous reports for human samples. This disparity results from biological, demographic, economic, and social differences across populations as well as from failures by most previous studies to account for variation in fitness introduced by nonreproductive individuals. Our results emphasize that the demographic, cultural, and technological changes of the last 10,000 y did not preclude the potential for natural and sexual selection in our species. PMID:22547810

Accounting for animal movement in estimation of resource selection functions: sampling and data analysis.

PubMed

Forester, James D; Im, Hae Kyung; Rathouz, Paul J

2009-12-01

Patterns of resource selection by animal populations emerge as a result of the behavior of many individuals. Statistical models that describe these population-level patterns of habitat use can miss important interactions between individual animals and characteristics of their local environment; however, identifying these interactions is difficult. One approach to this problem is to incorporate models of individual movement into resource selection models. To do this, we propose a model for step selection functions (SSF) that is composed of a resource-independent movement kernel and a resource selection function (RSF). We show that standard case-control logistic regression may be used to fit the SSF; however, the sampling scheme used to generate control points (i.e., the definition of availability) must be accommodated. We used three sampling schemes to analyze simulated movement data and found that ignoring sampling and the resource-independent movement kernel yielded biased estimates of selection. The level of bias depended on the method used to generate control locations, the strength of selection, and the spatial scale of the resource map. Using empirical or parametric methods to sample control locations produced biased estimates under stronger selection; however, we show that the addition of a distance function to the analysis substantially reduced that bias. Assuming a uniform availability within a fixed buffer yielded strongly biased selection estimates that could be corrected by including the distance function but remained inefficient relative to the empirical and parametric sampling methods. As a case study, we used location data collected from elk in Yellowstone National Park, USA, to show that selection and bias may be temporally variable. Because under constant selection the amount of bias depends on the scale at which a resource is distributed in the landscape, we suggest that distance always be included as a covariate in SSF analyses. This approach to

[The susceptibility of different animal species to synanthropic and natural populations of Trichinella].

PubMed

Artemenko, Iu G; Artemenko, L P

1997-01-01

Pigs have been found to be highly susceptible to the synanthropic (domestic) population of Trichinella [correction of Trachina] and weakly susceptible to the natural (native) one. Fur-bearing animals (polar foxes and foxes) are more susceptible to the natural population of Trichinella [correction of Trachina], but minks are equally sensible to the two variants of T. spiralis. In the host's body, synanthropic Trichinella [correction of Trachinas] form capsules of lemon-like, less frequently, oval shape, but the native population do round capsules. There is larval adaptation when Trichinella [correction of Trachina] larvae enter the nonspecific host's body after their prepassage through the organism of domestic carnivorous animals (cats, dogs). The pig is successfully infected with T. spiralis nativa via the cat or dog; the infection rate is approximately close to that observed during control infection of pigs with synanthropic Trichinella [correction of Trachina].

A Working Model of Natural Selection Illustrated by Table Tennis

ERIC Educational Resources Information Center

Dinc, Muhittin; Kilic, Selda; Aladag, Caner

2013-01-01

Natural selection is one of the most important topics in biology and it helps to clarify the variety and complexity of organisms. However, students in almost every stage of education find it difficult to understand the mechanism of natural selection and they can develop misconceptions about it. This article provides an active model of natural…

Animal welfare: an animal science approach.

PubMed

Koknaroglu, H; Akunal, T

2013-12-01

Increasing world population and demand for animal-derived protein puts pressure on animal production to meet this demand. For this purpose animal breeding efforts were conducted to obtain the maximum yield that the genetic makeup of the animals permits. Under the influence of economics which is the driving force behind animal production, animal farming became more concentrated and controlled which resulted in rearing animals under confinement. Since more attention was given on economics and yield per animal, animal welfare and behavior were neglected. Animal welfare which can be defined as providing environmental conditions in which animals can display all their natural behaviors in nature started gaining importance in recent years. This does not necessarily mean that animals provided with good management practices would have better welfare conditions as some animals may be distressed even though they are in good environmental conditions. Consumers are willing to pay more for welfare-friendly products (e.g.: free range vs caged egg) and this will change the animal production practices in the future. Thus animal scientists will have to adapt themselves for the changing animal welfare rules and regulations that differ for farm animal species and countries. In this review paper, animal welfare is discussed from an animal science standpoint. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Translational pain assessment: could natural animal models be the missing link?

PubMed

Klinck, Mary P; Mogil, Jeffrey S; Moreau, Maxim; Lascelles, B Duncan X; Flecknell, Paul A; Poitte, Thierry; Troncy, Eric

2017-09-01

Failure of analgesic drugs in clinical development is common. Along with the current "reproducibility crisis" in pain research, this has led some to question the use of animal models. Experimental models tend to comprise genetically homogeneous groups of young, male rodents in restricted and unvarying environments, and pain-producing assays that may not closely mimic the natural condition of interest. In addition, typical experimental outcome measures using thresholds or latencies for withdrawal may not adequately reflect clinical pain phenomena pertinent to human patients. It has been suggested that naturally occurring disease in veterinary patients may provide more valid models for the study of painful disease. Many painful conditions in animals resemble those in people. Like humans, veterinary patients are genetically diverse, often live to old age, and enjoy a complex environment, often the same as their owners. There is increasing interest in the development and validation of outcome measures for detecting pain in veterinary patients; these include objective (eg, locomotor activity monitoring, kinetic evaluation, quantitative sensory testing, and bioimaging) and subjective (eg, pain scales and quality of life scales) measures. Veterinary subject diversity, pathophysiological similarities to humans, and diverse outcome measures could yield better generalizability of findings and improved translation potential, potentially benefiting both humans and animals. The Comparative Oncology Trial Consortium in dogs has pawed the way for translational research, surmounting the challenges inherent in veterinary clinical trials. This review describes numerous conditions similarly applicable to pain research, with potential mutual benefits for human and veterinary clinicians, and their respective patients.

A Lesson on Evolution & Natural Selection

ERIC Educational Resources Information Center

Curtis, Anthony D.

2010-01-01

I describe three activities that allow students to explore the ideas of evolution, natural selection, extinction, mass extinction, and rates of evolutionary change by engaging a simple model using paper, pens, chalk, and a chalkboard. As a culminating activity that supports expository writing in the sciences, the students write an essay on mass…

Natural Selection as an Emergent Process: Instructional Implications

ERIC Educational Resources Information Center

Cooper, Robert A.

2017-01-01

Student reasoning about cases of natural selection is often plagued by errors that stem from miscategorising selection as a direct, causal process, misunderstanding the role of randomness, and from the intuitive ideas of intentionality, teleology and essentialism. The common thread throughout many of these reasoning errors is a failure to apply…

Human task animation from performance models and natural language input

NASA Technical Reports Server (NTRS)

Esakov, Jeffrey; Badler, Norman I.; Jung, Moon

1989-01-01

Graphical manipulation of human figures is essential for certain types of human factors analyses such as reach, clearance, fit, and view. In many situations, however, the animation of simulated people performing various tasks may be based on more complicated functions involving multiple simultaneous reaches, critical timing, resource availability, and human performance capabilities. One rather effective means for creating such a simulation is through a natural language description of the tasks to be carried out. Given an anthropometrically-sized figure and a geometric workplace environment, various simple actions such as reach, turn, and view can be effectively controlled from language commands or standard NASA checklist procedures. The commands may also be generated by external simulation tools. Task timing is determined from actual performance models, if available, such as strength models or Fitts' Law. The resulting action specification are animated on a Silicon Graphics Iris workstation in real-time.

The Limits of Natural Selection in a Nonequilibrium World.

PubMed

Brandvain, Yaniv; Wright, Stephen I

2016-04-01

Evolutionary theory predicts that factors such as a small population size or low recombination rate can limit the action of natural selection. The emerging field of comparative population genomics offers an opportunity to evaluate these hypotheses. However, classical theoretical predictions assume that populations are at demographic equilibrium. This assumption is likely to be violated in the very populations researchers use to evaluate selection's limits: populations that have experienced a recent shift in population size and/or effective recombination rates. Here we highlight theory and data analyses concerning limitations on the action of natural selection in nonequilibrial populations and argue that substantial care is needed to appropriately test whether species and populations show meaningful differences in selection efficacy. A move toward model-based inferences that explicitly incorporate nonequilibrium dynamics provides a promising approach to more accurately contrast selection efficacy across populations and interpret its significance. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hyperspectral small animal fluorescence imaging: spectral selection imaging

NASA Astrophysics Data System (ADS)

Leavesley, Silas; Jiang, Yanan; Patsekin, Valery; Hall, Heidi; Vizard, Douglas; Robinson, J. Paul

2008-02-01

Molecular imaging is a rapidly growing area of research, fueled by needs in pharmaceutical drug-development for methods for high-throughput screening, pre-clinical and clinical screening for visualizing tumor growth and drug targeting, and a growing number of applications in the molecular biology fields. Small animal fluorescence imaging employs fluorescent probes to target molecular events in vivo, with a large number of molecular targeting probes readily available. The ease at which new targeting compounds can be developed, the short acquisition times, and the low cost (compared to microCT, MRI, or PET) makes fluorescence imaging attractive. However, small animal fluorescence imaging suffers from high optical scattering, absorption, and autofluorescence. Much of these problems can be overcome through multispectral imaging techniques, which collect images at different fluorescence emission wavelengths, followed by analysis, classification, and spectral deconvolution methods to isolate signals from fluorescence emission. We present an alternative to the current method, using hyperspectral excitation scanning (spectral selection imaging), a technique that allows excitation at any wavelength in the visible and near-infrared wavelength range. In many cases, excitation imaging may be more effective at identifying specific fluorescence signals because of the higher complexity of the fluorophore excitation spectrum. Because the excitation is filtered and not the emission, the resolution limit and image shift imposed by acousto-optic tunable filters have no effect on imager performance. We will discuss design of the imager, optimizing the imager for use in small animal fluorescence imaging, and application of spectral analysis and classification methods for identifying specific fluorescence signals.

The meaning of seasonal changes, nature, and animals for adolescent girls' wellbeing in northern Finland: A qualitative descriptive study.

PubMed

Wiens, Varpu; Kyngäs, Helvi; Pölkki, Tarja

2016-01-01

Wellbeing is complex, holistic, and subjectively perceived. Issues such as gender, age, and environment seem to affect it. Therefore, the aim of this qualitative study was to describe the meaning of seasonal changes, nature, and animals towards 13-16-year-old girls' wellbeing in Northern Finland. In the spring of 2014, through purposive sampling, a total of 19 girls participated in semi-structured interviews from various parts of Northern Finland. The data were analysed using content analysis. Afterwards, the analysis combining the category participatory involvement with environment was found, and this consisted of three main categories: adaptation to seasonal changes, restorative nature, and empowering interactivity with animals. Seasonal changes had an effect on girls' wellbeing; in the summertime, they felt happy and vivacious, active, and outgoing. Instead, during the winter months, girls' mood and activity seemed to be lower and they felt lazier and depressed. Nature brought mainly positive feelings to girls; being in nature was experienced as liberating and relaxing, and it offered opportunities to relax and have sensory perceptions. Interaction with animals was perceived as empowering. They were experienced as altruistic and comforting companions. Animals were important to girls, and they contributed to girls' lives through positive effects towards their mental and physical wellbeing. Based on the results of this study, we can recommend that being in nature and interacting with animals should be supported because they seem to have benefits towards adolescent girls' health and wellbeing. In order to facilitate the negative effects of winter, the school days should be arranged in such a way that it would be possible for girls to have outdoor activities during the daytime. The challenge for the future is perhaps the purposeful utilisation of nature's and the animals' positive effects towards their wellbeing.

Ecology, sexual selection and speciation.

PubMed

Maan, Martine E; Seehausen, Ole

2011-06-01

The spectacular diversity in sexually selected traits among animal taxa has inspired the hypothesis that divergent sexual selection can drive speciation. Unfortunately, speciation biologists often consider sexual selection in isolation from natural selection, even though sexually selected traits evolve in an ecological context: both preferences and traits are often subject to natural selection. Conversely, while behavioural ecologists may address ecological effects on sexual communication, they rarely measure the consequences for population divergence. Herein, we review the empirical literature addressing the mechanisms by which natural selection and sexual selection can interact during speciation. We find that convincing evidence for any of these scenarios is thin. However, the available data strongly support various diversifying effects that emerge from interactions between sexual selection and environmental heterogeneity. We suggest that evaluating the evolutionary consequences of these effects requires a better integration of behavioural, ecological and evolutionary research. © 2011 Blackwell Publishing Ltd/CNRS.

Natural alcohol exposure: is ethanol the main substrate for alcohol dehydrogenases in animals?

PubMed

Hernández-Tobías, Aída; Julián-Sánchez, Adriana; Piña, Enrique; Riveros-Rosas, Héctor

2011-05-30

Alcohol dehydrogenase (ADH) activity is widely distributed in all phyla. In animals, three non-homologous NAD(P)(+)-dependent ADH protein families are reported. These arose independently throughout evolution and possess different structures and mechanisms of reaction: type I (medium-chain) ADHs are zinc-containing enzymes and comprise the most studied group in vertebrates; type II (short-chain) ADHs lack metal cofactor and have been extensively studied in Drosophila; and type III ADHs are iron-dependent/-activated enzymes that were initially identified only in microorganisms. The presence of these different ADHs in animals has been assumed to be a consequence of chronic exposure to ethanol. By far the most common natural source of ethanol is fermentation of fruit sugars by yeast, and available data support that this fruit trait evolved in concert with the characteristics of their frugivorous seed dispersers. Therefore, if the presence of ADHs in animals evolved as an adaptive response to dietary ethanol exposure, then it can be expected that the enzymogenesis of these enzymes began after the appearance of angiosperms with fleshy fruits, because substrate availability must precede enzyme selection. In this work, available evidence supporting this possibility is discussed. Phylogenetic analyses reveal that type II ADHs suffered several duplications, all of these restricted to flies (order Diptera). Induction of type II Adh by ethanol exposure, a positive correlation between ADH activity and ethanol resistance, and the fact that flies and type II Adh diversification occurred in concert with angiosperm diversification, strongly suggest that type II ADHs were recruited to allow larval flies to exploit new restricted niches with high ethanol content. In contrast, phyletic distribution of types I and III ADHs in animals showed that these appeared before angiosperms and land plants, independently of ethanol availability. Because these enzymes are not induced by ethanol

["Artificial animals etc." Popular natural history and bourgeois curiosity around 1900].

PubMed

Wessely, Christina

2008-01-01

During the 19th and early 20th century zoological gardens ranged among the most prominent places of popular natural history While aristocratic owners of earlier menageries installed animal collections mostly to symbolize their power over nature as well as to display their extensive diplomatic relations, the zoological gardens founded from the 1830s onwards all over Europe by members of the local bourgeois elites were supposed to mediate their social and political values by "enjoyably educating" a broader public. The new zoos were introduced as places at the antipodes of the frenzy, noise and motion of modern urban life, as spaces of pure, authentic nature whose observation would teach people a reasonable and responsible way of life in a civilised bourgeois community. Taking the Berlin Zoo as an example this paper questions these programmatic imaginations by showing how popular Naturkunde (natural history) was informed by cultures of urban entertainment and spectacle. It discusses the numerous relations and productive tensions that evolved out of the establishment of a "realm of nature" in the middle of the ever growing modern metropolis and investigates the consequences the zoo's rise as "the city's most important attraction" around the turn of the century had for the public perception of natural history as well as for the institution's scientific program.

Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

NASA Astrophysics Data System (ADS)

Keong, C. C.; Zin, W. M. Wan; Ibrahim, P.; Ibrahim, S.

2010-05-01

Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

Natural selection and infectious disease in human populations

PubMed Central

Karlsson, Elinor K.; Kwiatkowski, Dominic P.; Sabeti, Pardis C.

2015-01-01

The ancient biological 'arms race' between microbial pathogens and humans has shaped genetic variation in modern populations, and this has important implications for the growing field of medical genomics. As humans migrated throughout the world, populations encountered distinct pathogens, and natural selection increased the prevalence of alleles that are advantageous in the new ecosystems in both host and pathogens. This ancient history now influences human infectious disease susceptibility and microbiome homeostasis, and contributes to common diseases that show geographical disparities, such as autoimmune and metabolic disorders. Using new high-throughput technologies, analytical methods and expanding public data resources, the investigation of natural selection is leading to new insights into the function and dysfunction of human biology. PMID:24776769

Six Classroom Exercises to Teach Natural Selection to Undergraduate Biology Students

ERIC Educational Resources Information Center

Kalinowski, Steven T.; Leonard, Mary J.; Andrews, Tessa M.; Litt, Andrea R.

2013-01-01

Students in introductory biology courses frequently have misconceptions regarding natural selection. In this paper, we describe six activities that biology instructors can use to teach undergraduate students in introductory biology courses how natural selection causes evolution. These activities begin with a lesson introducing students to natural…

The Darwin cure for apiculture? Natural selection and managed honeybee health.

PubMed

Neumann, Peter; Blacquière, Tjeerd

2017-03-01

Recent major losses of managed honeybee, Apis mellifera, colonies at a global scale have resulted in a multitude of research efforts to identify the underlying mechanisms. Numerous factors acting singly and/or in combination have been identified, ranging from pathogens, over nutrition to pesticides. However, the role of apiculture in limiting natural selection has largely been ignored. This is unfortunate, because honeybees are more exposed to environmental stressors compared to other livestock and management can severely compromise bee health. Here, we briefly review apicultural factors that influence bee health and focus on those most likely interfering with natural selection, which offers a broad range of evolutionary applications for field practice. Despite intense breeding over centuries, natural selection appears to be much more relevant for the health of managed A. mellifera colonies than previously thought. We conclude that sustainable solutions for the apicultural sector can only be achieved by taking advantage of natural selection and not by attempting to limit it.

Artificial selection for structural color on butterfly wings and comparison with natural evolution

PubMed Central

Wasik, Bethany R.; Liew, Seng Fatt; Lilien, David A.; Dinwiddie, April J.; Noh, Heeso; Cao, Hui; Monteiro, Antónia

2014-01-01

Brilliant animal colors often are produced from light interacting with intricate nano-morphologies present in biological materials such as butterfly wing scales. Surveys across widely divergent butterfly species have identified multiple mechanisms of structural color production; however, little is known about how these colors evolved. Here, we examine how closely related species and populations of Bicyclus butterflies have evolved violet structural color from brown-pigmented ancestors with UV structural color. We used artificial selection on a laboratory model butterfly, B. anynana, to evolve violet scales from UV brown scales and compared the mechanism of violet color production with that of two other Bicyclus species, Bicyclus sambulos and Bicyclus medontias, which have evolved violet/blue scales independently via natural selection. The UV reflectance peak of B. anynana brown scales shifted to violet over six generations of artificial selection (i.e., in less than 1 y) as the result of an increase in the thickness of the lower lamina in ground scales. Similar scale structures and the same mechanism for producing violet/blue structural colors were found in the other Bicyclus species. This work shows that populations harbor large amounts of standing genetic variation that can lead to rapid evolution of scales’ structural color via slight modifications to the scales’ physical dimensions. PMID:25092295

Artificial selection for structural color on butterfly wings and comparison with natural evolution.

PubMed

Wasik, Bethany R; Liew, Seng Fatt; Lilien, David A; Dinwiddie, April J; Noh, Heeso; Cao, Hui; Monteiro, Antónia

2014-08-19

Brilliant animal colors often are produced from light interacting with intricate nano-morphologies present in biological materials such as butterfly wing scales. Surveys across widely divergent butterfly species have identified multiple mechanisms of structural color production; however, little is known about how these colors evolved. Here, we examine how closely related species and populations of Bicyclus butterflies have evolved violet structural color from brown-pigmented ancestors with UV structural color. We used artificial selection on a laboratory model butterfly, B. anynana, to evolve violet scales from UV brown scales and compared the mechanism of violet color production with that of two other Bicyclus species, Bicyclus sambulos and Bicyclus medontias, which have evolved violet/blue scales independently via natural selection. The UV reflectance peak of B. anynana brown scales shifted to violet over six generations of artificial selection (i.e., in less than 1 y) as the result of an increase in the thickness of the lower lamina in ground scales. Similar scale structures and the same mechanism for producing violet/blue structural colors were found in the other Bicyclus species. This work shows that populations harbor large amounts of standing genetic variation that can lead to rapid evolution of scales' structural color via slight modifications to the scales' physical dimensions.

Genic Variability and Strategies of Adaptation in Animals

PubMed Central

Selander, Robert K.; Kaufman, Donald W.

1973-01-01

Levels of genic heterozygosity, as measured by surveys of allozymic variation, are much lower in populations of large, mobile animals (most vertebrates) than in those of small, relatively immobile animals (most invertebrates). This difference is not consistent with theories relating variability to population size (species number) or dispersal ability (gene flow), but it is predicted by Levins' theory of adaptive strategies in relation to environmental uncertainty (“grain”). Mobility and degree of homeostatic control apparently are important factors influencing levels of genic heterozygosity in natural populations. The results argue indirectly that at least a major proportion of allozymic variation is maintained by natural selection. PMID:4515944

Darwinian natural selection: its enduring explanatory power

PubMed Central

2012-01-01

Evolutionary theory has never had a stronger scientific foundation than it does today. In a short review I hope to portray the deep commitment of today's biologists to Darwinian natural selection and to discoveries made since Darwin's time. In spite of the scientific advances in the century and a half since the publication of On the Origin of Species, Darwin still remains the principal author of modern evolutionary theory. He is one of the greatest contributors of all time to our understanding of nature. PMID:22481845

The habitat of Coccidioides spp. and the role of animals as reservoirs and disseminators in nature.

PubMed

Del Rocío Reyes-Montes, María; Pérez-Huitrón, María Ameyali; Ocaña-Monroy, Jorge Luis; Frías-De-León, María Guadalupe; Martínez-Herrera, Erick; Arenas, Roberto; Duarte-Escalante, Esperanza

2016-10-10

Coccidioidomycosis, a potentially fatal fungal infection, is considered an emergent mycotic disease because of the increased incidence of fungal infections registered over recent years. Infection occurs through the inhalation of arthroconidia from two main species of Coccidioides: Coccidioides immitis and C. posadasii, which are both endemic to arid and semi-arid regions of North America. Coccidioides species not only infect humans but can also infect other mammals (land, aquatic, wild or domestic), reptiles and birds. To obtain information regarding the habitat of Coccidioides spp. and the animals infected by this fungus and to identify the role that infected animals play as reservoirs and disseminators of this fungus in nature. A literature review was conducted to identify the habitat of Coccidioides spp. and the infected non-human animal species targeted by this fungus. This review allows us to suggest that Coccidioides spp. may be classified as halotolerant organisms; nevertheless, to perpetuate their life cycle, these organisms depend on different animal species (reservoirs) that serve as a link with the environment, by acting as disseminators of the fungi in nature.

Evolution of Students' Ideas about Natural Selection through a Constructivist Framework

ERIC Educational Resources Information Center

Baumgartner, Erin; Duncan, Kanesa

2009-01-01

Educating students about the process of evolution through natural selection is vitally important because not only is it the unifying theory of biological science, it is also widely regarded as difficult for students to fully comprehend. Anderson and colleagues (2002) describe alternative ideas and misconceptions about natural selection as highly…

Evolutionary genomics of animal personality.

PubMed

van Oers, Kees; Mueller, Jakob C

2010-12-27

Research on animal personality can be approached from both a phenotypic and a genetic perspective. While using a phenotypic approach one can measure present selection on personality traits and their combinations. However, this approach cannot reconstruct the historical trajectory that was taken by evolution. Therefore, it is essential for our understanding of the causes and consequences of personality diversity to link phenotypic variation in personality traits with polymorphisms in genomic regions that code for this trait variation. Identifying genes or genome regions that underlie personality traits will open exciting possibilities to study natural selection at the molecular level, gene-gene and gene-environment interactions, pleiotropic effects and how gene expression shapes personality phenotypes. In this paper, we will discuss how genome information revealed by already established approaches and some more recent techniques such as high-throughput sequencing of genomic regions in a large number of individuals can be used to infer micro-evolutionary processes, historical selection and finally the maintenance of personality trait variation. We will do this by reviewing recent advances in molecular genetics of animal personality, but will also use advanced human personality studies as case studies of how molecular information may be used in animal personality research in the near future.

Urbanization and biological invasion shape animal personalities.

PubMed

Lapiedra, Oriol; Chejanovski, Zachary; Kolbe, Jason J

2017-02-01

Novel selective pressures derived from human activities challenge the persistence of animal populations worldwide. Behavior is expected to be a major factor driving animals' responses to global change because it largely determines how animals interact with the environment. However, the role of individual variation in behavior to facilitate the persistence of animals in changing environments remains poorly understood. Here, we adopted an animal personality approach to investigate whether different behavioral traits allow animals to deal with two major components of global change: urbanization and biological invasions. By studying six populations of Anolis sagrei lizards, we found for the first time that anoles vary consistently in their behavior across different times and contexts. Importantly, these animal personalities were consistent in the wild and in captivity. We investigated whether behavioral traits are pulled in different directions by different components of global change. On the one hand, we found that lizards from urban areas differ from nearby forest lizards in that they were more tolerant of humans, less aggressive, bolder after a simulated predator attack, and they spent more time exploring new environments. Several of these risk-taking behaviors constituted a behavioral syndrome that significantly differed between urban and forest populations. On the other hand, the behavior of urban A. sagrei coexisting with the invasive predatory lizard Leiocephalus carinatus was associated with dramatic changes in their foraging niche. Overall, we provide evidence that differences in animal personalities facilitate the persistence of animals under novel selective regimes by producing adaptive behaviors relevant to their ecology such as predator avoidance. Our results suggest that natural selection can favor certain behaviors over others when animals are confronted with different ecological challenges posed by global change. Therefore, we underscore the need to

What Is "Natural"? Consumer Responses to Selected Ingredients.

PubMed

Chambers, Edgar; Chambers, Edgar; Castro, Mauricio

2018-04-23

Interest in “natural” food has grown enormously over the last decade. Because the United States government has not set a legal definition for the term “natural”, customers have formed their own sensory perceptions and opinions on what constitutes natural. In this study, we examined 20 ingredients to determine what consumers consider to be natural. Using a national database, 630 consumers were sampled (50% male and 50% female) online, and the results were analyzed using percentages and chi-square tests. No ingredient was considered natural by more than 69% of respondents. We found evidence that familiarity may play a major role in consumers’ determination of naturalness. We also found evidence that chemical sounding names and the age of the consumer have an effect on whether an ingredient and potentially a food is considered natural. Interestingly, a preference towards selecting GMO (genetically modified organisms) foods had no significant impact on perceptions of natural.

Opportunity for natural selection among five population groups of Manipur, North East India.

PubMed

Asghar, M; Meitei, S Y; Luxmi, Y; Achoubi, N; Meitei, K S; Murry, B; Sachdeva, M P; Saraswathy, K N

2014-01-01

Opportunity for natural selection among five population groups of Manipur in comparison with other North East Indian population has been studied. Crow's index as well as Johnston and Kensinger's index for natural selection were calculated based on differential fertility and mortality. The mortality component was found to be lower compared to fertility component in all the populations which may attribute to comparatively improved and easily accessible health care facilities. However, different selection pressures, artificial and natural, seem to be influencing the selection intensity through induced abortion and spontaneous abortion among the two non-tribal migrant groups: Bamon and Muslims, respectively. This study highlights the probable interaction of artificial and natural selection in determining the evolutionary fate of any population group.

Chiral Selective Chemistry Induced by Natural Selection of Spin-Polarized Electrons.

PubMed

Rosenberg, Richard A; Mishra, Debabrata; Naaman, Ron

2015-06-15

The search to understand the origin of homochirality in nature has been ongoing since the time of Pasteur. Previous work has shown that DNA can act as a spin filter for low-energy electrons and that spin-polarized secondary electrons produced by X-ray irradiation of a magnetic substrate can induce chiral selective chemistry. In the present work it is demonstrated that secondary electrons from a substrate that are transmitted through a chiral overlayer cause enantiomeric selective chemistry in an adsorbed adlayer. We determine the quantum yields (QYs) for dissociation of (R)- or (S)-epichlorohydrin adsorbed on a chiral self-assembled layer of DNA on gold and on bare gold (for control). The results show that there is a significant difference in the QYs between the two enantiomers when adsorbed on DNA, but none when they are adsorbed on bare Au. We propose that the effect results from natural spin filtering effects cause by the chiral monolayer. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Natural selection on plant physiological traits in an urban environment

NASA Astrophysics Data System (ADS)

Lambrecht, Susan C.; Mahieu, Stephanie; Cheptou, Pierre-Olivier

2016-11-01

Current rates of urbanization are creating new opportunities for studying urban plant ecology, but our knowledge of urban plant physiology lags behind that of other ecosystems. Moreover, higher temperatures, elevated CO2, and increased inorganic nitrogen deposition along with altered moisture regimes of urban as compared to rural areas creates a compelling analog for studying adaptations of plants to climate change. We grew plants under common conditions in a greenhouse to determine whether populations of Crepis sancta (Asteraceae) differed in phenological, morphological, and physiological traits. We also used a field experiment to test for natural selection on these traits in urban Montpellier, France. Urban plants flowered and senesced later than rural plants, and natural selection favored later phenology in the urban habitat. Natural selection also favored larger plants with more leaves, and increased photosynthesis and leaf nitrogen concentration. Ours is the first study to document selection on plant functional traits in an urban habitat and, as such, advances our understanding of urban plant ecology and possible adaptations to climate change.

The natural selection of altruistic traits.

PubMed

Boehm, C

1999-09-01

Proponents of the standard evolutionary biology paradigm explain human "altruism" in terms of either nepotism or strict reciprocity. On that basis our underlying nature is reduced to a function of inclusive fitness: human nature has to be totally selfish or nepotistic. Proposed here are three possible paths to giving costly aid to nonrelatives, paths that are controversial because they involve assumed pleiotropic effects or group selection. One path is pleiotropic subsidies that help to extend nepotistic helping behavior from close family to nonrelatives. Another is "warfare"-if and only if warfare recurred in the Paleolithic. The third and most plausible hypothesis is based on the morally based egalitarian syndrome of prehistoric hunter-gatherers, which reduced phenotypic variation at the within-group level, increased it at the between-group level, and drastically curtailed the advantages of free riders. In an analysis consistent with the fundamental tenets of evolutionary biology, these three paths are evaluated as explanations for the evolutionary development of a rather complicated human social nature.

Pairing Animal Cartoon Characters with Produce Stimulates Selection among Child Zoo Visitors

ERIC Educational Resources Information Center

Karpyn, Allison; Allen, Michael; Marks, Samantha; Filion, Nicole; Humphrey, Debora; Ye, Ai; May, Henry; Gardner, Meryl P.

2017-01-01

In order to address the pervasive trend of underconsumption of fruits and vegetables among children, we examined the hypothesis that children would be more likely to select fruits (apple slices, bananas, and oranges) and vegetables (baby carrots) when paired with animal cartoon image than when available without the character image. Tested in a…

The meaning of seasonal changes, nature, and animals for adolescent girls’ wellbeing in northern Finland: A qualitative descriptive study

PubMed Central

Wiens, Varpu; Kyngäs, Helvi; Pölkki, Tarja

2016-01-01

Wellbeing is complex, holistic, and subjectively perceived. Issues such as gender, age, and environment seem to affect it. Therefore, the aim of this qualitative study was to describe the meaning of seasonal changes, nature, and animals towards 13–16-year-old girls’ wellbeing in Northern Finland. In the spring of 2014, through purposive sampling, a total of 19 girls participated in semi-structured interviews from various parts of Northern Finland. The data were analysed using content analysis. Afterwards, the analysis combining the category participatory involvement with environment was found, and this consisted of three main categories: adaptation to seasonal changes, restorative nature, and empowering interactivity with animals. Seasonal changes had an effect on girls’ wellbeing; in the summertime, they felt happy and vivacious, active, and outgoing. Instead, during the winter months, girls’ mood and activity seemed to be lower and they felt lazier and depressed. Nature brought mainly positive feelings to girls; being in nature was experienced as liberating and relaxing, and it offered opportunities to relax and have sensory perceptions. Interaction with animals was perceived as empowering. They were experienced as altruistic and comforting companions. Animals were important to girls, and they contributed to girls’ lives through positive effects towards their mental and physical wellbeing. Based on the results of this study, we can recommend that being in nature and interacting with animals should be supported because they seem to have benefits towards adolescent girls’ health and wellbeing. In order to facilitate the negative effects of winter, the school days should be arranged in such a way that it would be possible for girls to have outdoor activities during the daytime. The challenge for the future is perhaps the purposeful utilisation of nature's and the animals’ positive effects towards their wellbeing. PMID:26905401

Genomics of coloration in natural animal populations.

PubMed

San-Jose, Luis M; Roulin, Alexandre

2017-07-05

Animal coloration has traditionally been the target of genetic and evolutionary studies. However, until very recently, the study of the genetic basis of animal coloration has been mainly restricted to model species, whereas research on non-model species has been either neglected or mainly based on candidate approaches, and thereby limited by the knowledge obtained in model species. Recent high-throughput sequencing technologies allow us to overcome previous limitations, and open new avenues to study the genetic basis of animal coloration in a broader number of species and colour traits, and to address the general relevance of different genetic structures and their implications for the evolution of colour. In this review, we highlight aspects where genome-wide studies could be of major utility to fill in the gaps in our understanding of the biology and evolution of animal coloration. The new genomic approaches have been promptly adopted to study animal coloration although substantial work is still needed to consider a larger range of species and colour traits, such as those exhibiting continuous variation or based on reflective structures. We argue that a robust advancement in the study of animal coloration will also require large efforts to validate the functional role of the genes and variants discovered using genome-wide tools.This article is part of the themed issue 'Animal coloration: production, perception, function and application'. © 2017 The Author(s).

Natural image statistics and low-complexity feature selection.

PubMed

Vasconcelos, Manuela; Vasconcelos, Nuno

2009-02-01

Low-complexity feature selection is analyzed in the context of visual recognition. It is hypothesized that high-order dependences of bandpass features contain little information for discrimination of natural images. This hypothesis is characterized formally by the introduction of the concepts of conjunctive interference and decomposability order of a feature set. Necessary and sufficient conditions for the feasibility of low-complexity feature selection are then derived in terms of these concepts. It is shown that the intrinsic complexity of feature selection is determined by the decomposability order of the feature set and not its dimension. Feature selection algorithms are then derived for all levels of complexity and are shown to be approximated by existing information-theoretic methods, which they consistently outperform. The new algorithms are also used to objectively test the hypothesis of low decomposability order through comparison of classification performance. It is shown that, for image classification, the gain of modeling feature dependencies has strongly diminishing returns: best results are obtained under the assumption of decomposability order 1. This suggests a generic law for bandpass features extracted from natural images: that the effect, on the dependence of any two features, of observing any other feature is constant across image classes.

Natural History of Innate Host Defense Peptides.

PubMed

Linde, A; Wachter, B; Höner, O P; Dib, L; Ross, C; Tamayo, A R; Blecha, F; Melgarejo, T

2009-12-01

Host defense peptides act on the forefront of innate immunity, thus playing a central role in the survival of animals and plants. Despite vast morphological changes in species through evolutionary history, all animals examined to date share common features in their innate immune defense strategies, hereunder expression of host defense peptides (HDPs). Most studies on HDPs have focused on humans, domestic and laboratory animals. More than a thousand different sequences have been identified, yet data on HDPs in wild-living animals are sparse. The biological functions of HDPs include broad-spectrum antimicrobial activity and immunomodulation. Natural selection and coevolutionary host-pathogen arms race theory suggest that the extent and specificity of the microbial load influences the spectrum and potency of HDPs in different species. Individuals of extant species-that have lived for an extended period in evolutionary history amid populations with intact processes of natural selection-likely possess the most powerful and well-adapted "natural antibiotics". Research on the evolutionary history of the innate defense system and the host in context of the consequences of challenges as well as the efficacy of the innate immune system under natural conditions is therefore of immediate interest. This review focuses on evolutionary aspects of immunophysiology, with emphasis on innate effector molecules. Studies on host defense in wild-living animals may significantly enhance our understanding of inborn immune mechanisms, and help identify molecules that may assist us to cope better with the increasing microbial challenges that likely follow from the continuous amplification of biodiversity levels on Earth.

Food choices at lunch during the third year of life: high selection of animal and starchy foods but avoidance of vegetables.

PubMed

Nicklaus, Sophie; Boggio, Vincent; Issanchou, Sylvie

2005-07-01

The objective was to show patterns of food selection by 2- to 3-y-old children for a wide variety of foods in a self-service cafeteria and to assess the effect of individual variables (gender, BMI, mode of feeding after birth and rank in sibship). In a nursery self-service canteen, food choices at lunch made by children (n=418, 24-36 mo; 109 observations per child on average) were recorded by trained assistants who monitored portion size. An offer of eight dishes (animal products, starchy foods, combination dishes, vegetables and dairy products), excluding dessert-type foods, was proposed. Choice level was calculated for each food. Analysis of variance was used to compare choices for the various foods and to assess the effect of the individual variables. The choice of a food largely depended upon its nature: animal products, starchy foods and their combinations were widely chosen, whereas vegetables were not often selected; the choice for dairy products depended upon the type. The mode of preparation of the food influenced its choice. Segmenting products were identified; however, except for cheeses, a given child did not refuse an entire food category. Children's characteristics did not explain the choice variability. At the age of 2 to 3 y, children preferentially choose animal products and starchy foods and avoid vegetables; the high individual variability of their food choices could be related to previous food experiences.

9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

Code of Federal Regulations, 2013 CFR

2013-01-01

... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

Code of Federal Regulations, 2014 CFR

2014-01-01

... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

9 CFR 79.4 - Designation of scrapie-positive animals, high-risk animals, exposed animals, suspect animals...

Code of Federal Regulations, 2012 CFR

2012-01-01

... designated scrapie epidemiologist may conduct testing of animals if he or she determines such testing is... epidemiologist will select animals for testing in a manner that will provide a 95 percent confidence of detecting... lambed in the flock are available for testing, may limit the testing to all exposed and suspect animals...

Cancer is an adaptation that selects in animals against energy dissipation.

PubMed

Muller, Anthonie W J

2017-07-01

As cancer usually follows reproduction, it is generally assumed that cancer does not select. Graham has however argued that juvenile cancer, which precedes reproduction, could during evolution have implemented a "cancer selection" that resulted in novel traits that suppress this juvenile cancer; an example is protection against UV sunlight-induced cancer, required for the emergence of terrestrial animals from the sea. We modify the cancer selection mechanism to the posited "cancer adaptation" mechanism, in which juvenile mortality is enhanced through the diminished care received by juveniles from their (grand) parents when these suffer from cancer in old age. Moreover, it is posited that the cancer adaptation selects against germline "dissipative genes", genes that result in enhanced free energy dissipation. Cancer's progression is interpreted as a cascade at increasing scale of repeated amplification of energy dissipation, a cascade involving heat shock, the Warburg effect, the cytokine IL-6, tumours, and hypermetabolism. Disturbance of any physiological process must enhance energy dissipation if the animal remains functioning normally, what explains multicausality, why "everything gives you cancer". The hypothesis thus comprises two newly invoked partial processes-diminished (grand) parental care and dissipation amplification-and results in a "selection against enhanced energy dissipation" which gives during evolution the benefit of energy conservation. Due to this benefit, cancer would essentially be an adaptation, and not a genetic disease, as assumed in the "somatic mutation theory". Cancer by somatic mutations is only a side process. The cancer adaptation hypothesis is substantiated by (1) cancer's extancy, (2) the failure of the somatic mutation theory, (3) cancer's initiation by a high temperature, (4) the interpretation of cancer's progression as a thermal process, and (5) the interpretation of tumours as organs that implement thermogenesis. The hypothesis

Selective MAO-B inhibitors: a lesson from natural products.

PubMed

Carradori, Simone; D'Ascenzio, Melissa; Chimenti, Paola; Secci, Daniela; Bolasco, Adriana

2014-02-01

Monoamine oxidases (MAOs) are mitochondrial bound enzymes, which catalyze the oxidative deamination of monoamine neurotransmitters. Inside the brain, MAOs are present in two isoforms: MAO-A and MAO-B. The activity of MAO-B is generally higher in patients affected by neurodegenerative diseases like Alzheimer's and Parkinson's. Therefore, the search for potent and selective MAO-B inhibitors is still a challenge for medicinal chemists. Nature has always been a source of inspiration for the discovery of new lead compounds. Moreover, natural medicine is a major component in all traditional medicine systems. In this review, we present the latest discoveries in the search for selective MAO-B inhibitors from natural sources. For clarity, compounds have been classified on the basis of structural analogy or source: flavonoids, xanthones, tannins, proanthocyanidins, iridoid glucosides, curcumin, alkaloids, cannabinoids, and natural sources extracts. MAO inhibition values reported in the text are not always consistent due to the high variability of MAO sources (bovine, pig, rat brain or liver, and human) and to the heterogeneity of the experimental protocols used.

Natural Selection in Cancer Biology: From Molecular Snowflakes to Trait Hallmarks

PubMed Central

Fortunato, Angelo; Boddy, Amy; Mallo, Diego; Aktipis, Athena; Maley, Carlo C.; Pepper, John W.

2017-01-01

Evolution by natural selection is the conceptual foundation for nearly every branch of biology and increasingly also for biomedicine and medical research. In cancer biology, evolution explains how populations of cells in tumors change over time. It is a fundamental question whether this evolutionary process is driven primarily by natural selection and adaptation or by other evolutionary processes such as founder effects and drift. In cancer biology, as in organismal evolutionary biology, there is controversy about this question and also about the use of adaptation through natural selection as a guiding framework for research. In this review, we discuss the differences and similarities between evolution among somatic cells versus evolution among organisms. We review what is known about the parameters and rate of evolution in neoplasms, as well as evidence for adaptation. We conclude that adaptation is a useful framework that accurately explains the defining characteristics of cancer. Further, convergent evolution through natural selection provides the only satisfying explanation both for how a group of diverse pathologies have enough in common to usefully share the descriptive label of “cancer” and for why this convergent condition becomes life-threatening. PMID:28148564

Natural Selection in Cancer Biology: From Molecular Snowflakes to Trait Hallmarks.

PubMed

Fortunato, Angelo; Boddy, Amy; Mallo, Diego; Aktipis, Athena; Maley, Carlo C; Pepper, John W

2017-02-01

Evolution by natural selection is the conceptual foundation for nearly every branch of biology and increasingly also for biomedicine and medical research. In cancer biology, evolution explains how populations of cells in tumors change over time. It is a fundamental question whether this evolutionary process is driven primarily by natural selection and adaptation or by other evolutionary processes such as founder effects and drift. In cancer biology, as in organismal evolutionary biology, there is controversy about this question and also about the use of adaptation through natural selection as a guiding framework for research. In this review, we discuss the differences and similarities between evolution among somatic cells versus evolution among organisms. We review what is known about the parameters and rate of evolution in neoplasms, as well as evidence for adaptation. We conclude that adaptation is a useful framework that accurately explains the defining characteristics of cancer. Further, convergent evolution through natural selection provides the only satisfying explanation both for how a group of diverse pathologies have enough in common to usefully share the descriptive label of "cancer" and for why this convergent condition becomes life-threatening. Copyright © 2017 Cold Spring Harbor Laboratory Press; all rights reserved.

Considerations in the selection and conditioning of Old World monkeys for laboratory research: animals from domestic sources.

PubMed

Capitanio, John P; Kyes, Randall C; Fairbanks, Lynn A

2006-01-01

Nonhuman primates from domestic sources constitute an important resource for the research community. The life history of the Old World monkey species that comprise the bulk of this resource is described, and issues that colony managers and researchers alike should consider regarding animal selection (e.g., species, age, sex, rearing history, temperament, genotype, viral status, geographic origin) are discussed. Preparation of domestically bred animals for research usually involves some combination of social separation, relocation, resocialization, alterations in physical space, photoperiod, and diet, as well as exposure to novel environments. The research literature that has focused on these issues is reviewed, and authors suggest that once animals have been assigned to their project housing situation, a period ranging up to 3 mo (depending on the magnitude of the change in housing) might be warranted before an experimental protocol should begin. Attention to issues of animal selection and conditioning by both researchers and colony managers can lead to the shared goal of high-quality research that utilizes the minimal number of animals.

Contributions of natural and sexual selection to the evolution of premating reproductive isolation: a research agenda.

PubMed

Safran, Rebecca J; Scordato, Elizabeth S C; Symes, Laurel B; Rodríguez, Rafael L; Mendelson, Tamra C

2013-11-01

Speciation by divergent natural selection is well supported. However, the role of sexual selection in speciation is less well understood due to disagreement about whether sexual selection is a mechanism of evolution separate from natural selection, as well as confusion about various models and tests of sexual selection. Here, we outline how sexual selection and natural selection are different mechanisms of evolutionary change, and suggest that this distinction is critical when analyzing the role of sexual selection in speciation. Furthermore, we clarify models of sexual selection with respect to their interaction with ecology and natural selection. In doing so, we outline a research agenda for testing hypotheses about the relative significance of divergent sexual and natural selection in the evolution of reproductive isolation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic evidence for natural selection in humans in the contemporary United States.

PubMed

Beauchamp, Jonathan P

2016-07-12

Recent findings from molecular genetics now make it possible to test directly for natural selection by analyzing whether genetic variants associated with various phenotypes have been under selection. I leverage these findings to construct polygenic scores that use individuals' genotypes to predict their body mass index, educational attainment (EA), glucose concentration, height, schizophrenia, total cholesterol, and (in females) age at menarche. I then examine associations between these scores and fitness to test whether natural selection has been occurring. My study sample includes individuals of European ancestry born between 1931 and 1953 who participated in the Health and Retirement Study, a representative study of the US population. My results imply that natural selection has been slowly favoring lower EA in both females and males, and are suggestive that natural selection may have favored a higher age at menarche in females. For EA, my estimates imply a rate of selection of about -1.5 mo of education per generation (which pales in comparison with the increases in EA observed in contemporary times). Although they cannot be projected over more than one generation, my results provide additional evidence that humans are still evolving-albeit slowly, especially compared with the rapid changes that have occurred over the past few generations due to cultural and environmental factors.

Genetic evidence for natural selection in humans in the contemporary United States

PubMed Central

Beauchamp, Jonathan P.

2016-01-01

Recent findings from molecular genetics now make it possible to test directly for natural selection by analyzing whether genetic variants associated with various phenotypes have been under selection. I leverage these findings to construct polygenic scores that use individuals’ genotypes to predict their body mass index, educational attainment (EA), glucose concentration, height, schizophrenia, total cholesterol, and (in females) age at menarche. I then examine associations between these scores and fitness to test whether natural selection has been occurring. My study sample includes individuals of European ancestry born between 1931 and 1953 who participated in the Health and Retirement Study, a representative study of the US population. My results imply that natural selection has been slowly favoring lower EA in both females and males, and are suggestive that natural selection may have favored a higher age at menarche in females. For EA, my estimates imply a rate of selection of about −1.5 mo of education per generation (which pales in comparison with the increases in EA observed in contemporary times). Although they cannot be projected over more than one generation, my results provide additional evidence that humans are still evolving—albeit slowly, especially compared with the rapid changes that have occurred over the past few generations due to cultural and environmental factors. PMID:27402742

Historical evidence for nature disconnection in a 70-year time series of Disney animated films.

PubMed

Prévot-Julliard, Anne-Caroline; Julliard, Romain; Clayton, Susan

2015-08-01

The assumed ongoing disconnection between humans and nature in Western societies represents a profoundly challenging conservation issue. Here, we demonstrate one manifestation of this nature disconnection, via an examination of the representation of natural settings in a 70-year time series of Disney animated films. We found that natural settings are increasingly less present as a representation of outdoor environments in these films. Moreover, these drawn natural settings tend to be more and more human controlled and are less and less complex in terms of the biodiversity they depict. These results demonstrate the increasing nature disconnection of the filmmaking teams, which we consider as a proxy of the Western relation to nature. Additionally, because nature experience of children is partly based on movies, the depleted representation of biodiversity in outdoor environments of Disney films may amplify the current disconnection from nature for children. This reduction in exposure to nature may hinder the implementation of biodiversity conservation measures. © The Author(s) 2014.

Conceptualizing the autism spectrum in terms of natural selection and behavioral ecology: the solitary forager hypothesis.

PubMed

Reser, Jared Edward

2011-05-21

This article reviews etiological and comparative evidence supporting the hypothesis that some genes associated with the autism spectrum were naturally selected and represent the adaptive benefits of being cognitively suited for solitary foraging. People on the autism spectrum are conceptualized here as ecologically competent individuals that could have been adept at learning and implementing hunting and gathering skills in the ancestral environment. Upon independence from their mothers, individuals on the autism spectrum may have been psychologically predisposed toward a different life-history strategy, common among mammals and even some primates, to hunt and gather primarily on their own. Many of the behavioral and cognitive tendencies that autistic individuals exhibit are viewed here as adaptations that would have complemented a solitary lifestyle. For example, the obsessive, repetitive and systemizing tendencies in autism, which can be mistakenly applied toward activities such as block stacking today, may have been focused by hunger and thirst toward successful food procurement in the ancestral past. Both solitary mammals and autistic individuals are low on measures of gregariousness, socialization, direct gazing, eye contact, facial expression, facial recognition, emotional engagement, affiliative need and other social behaviors. The evolution of the neurological tendencies in solitary species that predispose them toward being introverted and reclusive may hold important clues for the evolution of the autism spectrum and the natural selection of autism genes. Solitary animals are thought to eschew unnecessary social contact as part of a foraging strategy often due to scarcity and wide dispersal of food in their native environments. It is thought that the human ancestral environment was often nutritionally sparse as well, and this may have driven human parties to periodically disband. Inconsistencies in group size must have led to inconsistencies in the manner

Kin-selected cooperation without lifetime monogamy: human insights and animal implications.

PubMed

Kramer, Karen L; Russell, Andrew F

2014-11-01

Recent phylogenetic analyses suggest that monogamy precedes the evolution of cooperative breeding involving non-breeding helpers. The rationale: only through monogamy can helper-recipient relatedness coefficients match those of parent-offspring. Given that humans are cooperative breeders, these studies imply a monogamy bottleneck during hominin evolution. However, evidence from multiple sources is not compelling. In reconciliation, we propose that selection against cooperative breeding under alternative mating patterns will be mitigated by: (i) kin discrimination, (ii) reduced birth-intervals, and (iii) constraints on independent breeding, particularly for premature and post-fertile individuals. We suggest that such alternatives require consideration to derive a complete picture of the selection pressures acting on the evolution of cooperative breeding in humans and other animals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Magnetic maps in animals: nature's GPS.

PubMed

Lohmann, Kenneth J; Lohmann, Catherine M F; Putman, Nathan F

2007-11-01

Diverse animals detect the Earth's magnetic field and use it as a cue in orientation and navigation. Most research on magnetoreception has focused on the directional or ;compass' information that can be extracted from the Earth's field. Because the field varies predictably across the surface of the globe, however, it also provides a potential source of positional or 'map' information, which some animals use to steer themselves along migratory pathways or to navigate toward specific target areas. The use of magnetic positional information has been demonstrated in several diverse animals including sea turtles, spiny lobsters, newts and birds, suggesting that such systems are phylogenetically widespread and can function over a wide range of spatial scales. These ;magnetic maps' have not yet been fully characterized. They may be organized in several fundamentally different ways, some of which bear little resemblance to human maps, and they may also be used in conjunction with unconventional navigational strategies.

ANTI-ULCEROGENIC EFFICACY AND MECHANISMS OF EDIBLE AND NATURAL INGREDIENTS IN NSAID-INDUCED ANIMAL MODELS.

PubMed

Bi, Weiping; Hu, Lizhi; Man, Mao-Qiang

2017-01-01

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a class of the most commonly used medicines and proven to be effective for certain disorders. Some people use NSAIDs on daily basis for preventive purpose. But a variety of severe side effects can be induced by NSAIDs. Studies have shown that edible natural ingredients exhibit preventive benefit of gastric ulcer. This paper reviews the efficacy and safety of edible natural ingredients in preventing the development of gastric ulcer induced by NSAIDs in animal models. A systematic literature search was conducted on PubMed, using the terms "herbal medicines" and "gastric ulcer", "herbal medicines" and "peptic ulcer", "food" and "peptic ulcer", "food" and "gastric ulcer", "natural ingredient" and "peptic ulcer", "natural ingredient" and "gastric ulcer", "alternative medicine" and "peptic ulcer", "alternative medicine" and "gastric ulcer", "complementary medicine" and "peptic ulcer", "complementary medicine" and "gastric ulcer" in papers published in English between January 1, 1960 and January 31, 2016, resulting in a total of 6146 articles containing these terms. After exclusion of studies not related prevention, not in NSAID model or using non-edible natural ingredients, 54 articles were included in this review. Numerous studies have demonstrated that edible natural ingredients exhibit antiulcerogenic benefit in NSAID-induced animal models. The mechanisms by which edible, ingredient-induced anti-ulcerogenic effects include stimulation of mucous cell proliferation, antioxidation, inhibition of gastric acid secretion, as well as inhibition of H (+), K (+)- ATPase activities. Utilization of edible, natural ingredients could be a safe, valuable alternative to prevent the development of NSAID-induced gastric ulcer, particularly for the subjects who are long-term users of NSAIDs.

A review of the evolution of animal colour vision and visual communication signals.

PubMed

Osorio, D; Vorobyev, M

2008-09-01

The visual displays of animals and plants are often colourful, and colour vision allows animals to respond to these signals as they forage for food, choose mates and so-forth. This article discusses the evolutionary relationship between photoreceptor spectral sensitivities of four groups of land animals--birds, butterflies, primates and hymenopteran insects (bees and wasps)--, the colour signals that are relevant to them, and how understanding is informed by models of spectral coding and colour vision. Although the spectral sensitivities of photoreceptors are known to vary adaptively under natural selection there is little evidence that those of hymenopterans, birds and primates are specifically adapted to the reflectance spectra of food plants or animal visual signals. On the other hand, the colours of fruit, flowers and feathers may have evolved to be more discriminable for the colour vision of their natural receivers than for other groups of animals. Butterflies are unusual in that they have enjoyed a major radiation in receptor numbers and spectral sensitivities. The reasons for the radiation and diversity of butterfly colour vision remain unknown, but may include their need to find food plants and to select mates.

The Impact of Designing and Evaluating Molecular Animations on How Well Middle School Students Understand the Particulate Nature of Matter

ERIC Educational Resources Information Center

Chang, Hsin-Yi; Quintana, Chris; Krajcik, Joseph S.

2010-01-01

In this study, we investigated whether the understanding of the particulate nature of matter by students was improved by allowing them to design and evaluate molecular animations of chemical phenomena. We developed Chemation, a learner-centered animation tool, to allow seventh-grade students to construct flipbook-like simple animations to show…

Forest fragmentation and selective logging have inconsistent effects on multiple animal-mediated ecosystem processes in a tropical forest.

PubMed

Schleuning, Matthias; Farwig, Nina; Peters, Marcell K; Bergsdorf, Thomas; Bleher, Bärbel; Brandl, Roland; Dalitz, Helmut; Fischer, Georg; Freund, Wolfram; Gikungu, Mary W; Hagen, Melanie; Garcia, Francisco Hita; Kagezi, Godfrey H; Kaib, Manfred; Kraemer, Manfred; Lung, Tobias; Naumann, Clas M; Schaab, Gertrud; Templin, Mathias; Uster, Dana; Wägele, J Wolfgang; Böhning-Gaese, Katrin

2011-01-01

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the

Forest Fragmentation and Selective Logging Have Inconsistent Effects on Multiple Animal-Mediated Ecosystem Processes in a Tropical Forest

PubMed Central

Schleuning, Matthias; Farwig, Nina; Peters, Marcell K.; Bergsdorf, Thomas; Bleher, Bärbel; Brandl, Roland; Dalitz, Helmut; Fischer, Georg; Freund, Wolfram; Gikungu, Mary W.; Hagen, Melanie; Garcia, Francisco Hita; Kagezi, Godfrey H.; Kaib, Manfred; Kraemer, Manfred; Lung, Tobias; Schaab, Gertrud; Templin, Mathias; Uster, Dana; Wägele, J. Wolfgang; Böhning-Gaese, Katrin

2011-01-01

Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes show that the

The Nature of Selected English Teachers' Online Participation

ERIC Educational Resources Information Center

Rodesiler, Luke

2015-01-01

This article documents an investigation into the nature of selected secondary English teachers' online participation across platforms (i.e., blogs, microblogs, social networking sites) as they explored issues related to teaching, learning, and literacy. Ethnographic content analysis of online artifacts generated over approximately 10 months…

Genetic Selection to Enhance Animal Welfare Using Meat Inspection Data from Slaughter Plants.

PubMed

Mathur, Pramod K; Vogelzang, Roos; Mulder, Herman A; Knol, Egbert F

2018-01-24

Animal health and welfare are monitored during meat inspection in many slaughter plants around the world. Carcasses are examined by meat inspectors and remarks are made with respect to different diseases, injuries, and other abnormalities. This is a valuable data resource for disease prevention and enhancing animal welfare, but it is rarely used for this purpose. Records on carcass remarks on 140,375 finisher pigs were analyzed to investigate the possibility of genetic selection to reduce the risk of the most prevalent diseases and indicators of suboptimal animal welfare. As part of this, effects of some non-genetic factors such as differences between farms, sexes, and growth rates were also examined. The most frequent remarks were pneumonia (15.4%), joint disorders (9.8%), pleuritis (4.7%), pericarditis (2.3%), and liver lesions (2.2%). Joint disorders were more frequent in boars than in gilts. There were also significant differences between farms. Pedigree records were available for 142,324 pigs from 14 farms and were used for genetic analysis. Heritability estimates for pneumonia, pleuritis, pericarditis, liver lesions, and joint disorders were 0.10, 0.09, 0.14, 0.24, and 0.17 on the liability scale, respectively, suggesting the existence of substantial genetic variation. This was further confirmed though genome wide associations using deregressed breeding values as phenotypes. The genetic correlations between these remarks and finishing traits were small but mostly negative, suggesting the possibility of enhancing pig health and welfare simultaneously with genetic improvement in finishing traits. A selection index based on the breeding values for these traits and their economic values was developed. This index is used to enhance animal welfare in pig farms.

Determining the Effect of Natural Selection on Linked Neutral Divergence across Species.

PubMed

Phung, Tanya N; Huber, Christian D; Lohmueller, Kirk E

2016-08-01

A major goal in evolutionary biology is to understand how natural selection has shaped patterns of genetic variation across genomes. Studies in a variety of species have shown that neutral genetic diversity (intra-species differences) has been reduced at sites linked to those under direct selection. However, the effect of linked selection on neutral sequence divergence (inter-species differences) remains ambiguous. While empirical studies have reported correlations between divergence and recombination, which is interpreted as evidence for natural selection reducing linked neutral divergence, theory argues otherwise, especially for species that have diverged long ago. Here we address these outstanding issues by examining whether natural selection can affect divergence between both closely and distantly related species. We show that neutral divergence between closely related species (e.g. human-primate) is negatively correlated with functional content and positively correlated with human recombination rate. We also find that neutral divergence between distantly related species (e.g. human-rodent) is negatively correlated with functional content and positively correlated with estimates of background selection from primates. These patterns persist after accounting for the confounding factors of hypermutable CpG sites, GC content, and biased gene conversion. Coalescent models indicate that even when the contribution of ancestral polymorphism to divergence is small, background selection in the ancestral population can still explain a large proportion of the variance in divergence across the genome, generating the observed correlations. Our findings reveal that, contrary to previous intuition, natural selection can indirectly affect linked neutral divergence between both closely and distantly related species. Though we cannot formally exclude the possibility that the direct effects of purifying selection drive some of these patterns, such a scenario would be possible only

Determining the Effect of Natural Selection on Linked Neutral Divergence across Species

PubMed Central

Phung, Tanya N.; Lohmueller, Kirk E.

2016-01-01

A major goal in evolutionary biology is to understand how natural selection has shaped patterns of genetic variation across genomes. Studies in a variety of species have shown that neutral genetic diversity (intra-species differences) has been reduced at sites linked to those under direct selection. However, the effect of linked selection on neutral sequence divergence (inter-species differences) remains ambiguous. While empirical studies have reported correlations between divergence and recombination, which is interpreted as evidence for natural selection reducing linked neutral divergence, theory argues otherwise, especially for species that have diverged long ago. Here we address these outstanding issues by examining whether natural selection can affect divergence between both closely and distantly related species. We show that neutral divergence between closely related species (e.g. human-primate) is negatively correlated with functional content and positively correlated with human recombination rate. We also find that neutral divergence between distantly related species (e.g. human-rodent) is negatively correlated with functional content and positively correlated with estimates of background selection from primates. These patterns persist after accounting for the confounding factors of hypermutable CpG sites, GC content, and biased gene conversion. Coalescent models indicate that even when the contribution of ancestral polymorphism to divergence is small, background selection in the ancestral population can still explain a large proportion of the variance in divergence across the genome, generating the observed correlations. Our findings reveal that, contrary to previous intuition, natural selection can indirectly affect linked neutral divergence between both closely and distantly related species. Though we cannot formally exclude the possibility that the direct effects of purifying selection drive some of these patterns, such a scenario would be possible only

ANIMAL BEHAVIOR AND WELL-BEING SYMPOSIUM: Interaction between coping style/personality, stress, and welfare: Relevance for domestic farm animals.

PubMed

Koolhaas, J M; Van Reenen, C G

2016-06-01

This paper will argue that understanding animal welfare and the individual vulnerability to stress-related disease requires a fundamental understanding of functional individual variation as it occurs in nature as well as the underlying neurobiology and neuroendocrinology. Ecological studies in feral populations of mice, fish, and birds start to recognize the functional significance of phenotypes that individually differ in their behavioral and neuroendocrine response to environmental challenge. Recent studies indicate that the individual variation within a species may buffer the species for strong fluctuations in the natural habitat. Similarly, evolutionary ancient behavioral trait characteristics have now been identified in a range of domestic farm animals including cattle, pigs, and horses. Individual variation in behavior can be summarized in a 3-dimensional model with coping style, emotionality, and sociality as independent dimensions. These dimensions can be considered trait characteristics that are stable over time and across situations within the individual. This conceptual model has several consequences. First, the coping style dimension is strongly associated with differential stress vulnerability. Social stress studies show that proactive individuals are resilient under stable environmental conditions but vulnerable when outcome expectancies are violated. Reactive individuals are, in fact, rather flexible and seem to adapt more easily to a changing environment. A second consequence relates to genetics and breeding. Genetic selection for one trait usually implies selection for other traits as well. It is discussed that a more balanced breeding program that takes into account biologically functional temperamental traits will lead to more robust domestic farm animals. Finally, the relationship between temperamental traits, animal production, fitness, and welfare is discussed.

Effective Assessment: Probing Students' Understanding of Natural Selection

ERIC Educational Resources Information Center

Stern, Luli

2004-01-01

Evolution by natural selection provides the conceptual framework upon which much of modern biology is based: therefore understanding core ideas about biological evolution is an essential part of scientific literacy. Nonetheless, research repeatedly shows that high school and college students have difficulties understanding the notion of natural…

ANTI-ULCEROGENIC EFFICACY AND MECHANISMS OF EDIBLE AND NATURAL INGREDIENTS IN NSAID-INDUCED ANIMAL MODELS

PubMed Central

Bi, Weiping; Hu, Lizhi; Man, Mao-Qiang

2017-01-01

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are a class of the most commonly used medicines and proven to be effective for certain disorders. Some people use NSAIDs on daily basis for preventive purpose. But a variety of severe side effects can be induced by NSAIDs. Studies have shown that edible natural ingredients exhibit preventive benefit of gastric ulcer. This paper reviews the efficacy and safety of edible natural ingredients in preventing the development of gastric ulcer induced by NSAIDs in animal models. Methods: A systematic literature search was conducted on PubMed, using the terms “herbal medicines” and “gastric ulcer”, “herbal medicines” and “peptic ulcer”, “food” and “peptic ulcer”, “food” and “gastric ulcer”, “natural ingredient” and “peptic ulcer”, “natural ingredient” and “gastric ulcer”, “alternative medicine” and “peptic ulcer”, “alternative medicine” and “gastric ulcer”, “complementary medicine” and “peptic ulcer”, “complementary medicine” and “gastric ulcer” in papers published in English between January 1, 1960 and January 31, 2016, resulting in a total of 6146 articles containing these terms. After exclusion of studies not related prevention, not in NSAID model or using non-edible natural ingredients, 54 articles were included in this review. Results: Numerous studies have demonstrated that edible natural ingredients exhibit antiulcerogenic benefit in NSAID-induced animal models. The mechanisms by which edible, ingredient-induced anti-ulcerogenic effects include stimulation of mucous cell proliferation, antioxidation, inhibition of gastric acid secretion, as well as inhibition of H (+), K (+)- ATPase activities. Utilization of edible, natural ingredients could be a safe, valuable alternative to prevent the development of NSAID-induced gastric ulcer, particularly for the subjects who are long-term users of NSAIDs. PMID:28638885

The Creativity of Natural Selection? Part I: Darwin, Darwinism, and the Mutationists.

PubMed

Beatty, John

2016-12-01

This is the first of a two-part essay on the history of debates concerning the creativity of natural selection, from Darwin through the evolutionary synthesis and up to the present. Here I focus on the mid-late nineteenth century to the early twentieth, with special emphasis on early Darwinism and its critics, the self-styled "mutationists." The second part focuses on the evolutionary synthesis and some of its critics, especially the "neutralists" and "neo-mutationists." Like Stephen Gould, I consider the creativity of natural selection to be a key component of what has traditionally counted as "Darwinism." I argue that the creativity of natural selection is best understood in terms of (1) selection initiating evolutionary change, and (2) selection being responsible for the presence of the variation it acts upon, for example by directing the course of variation. I consider the respects in which both of these claims sound non-Darwinian, even though they have long been understood by supporters and critics alike to be virtually constitutive of Darwinism.

Dangerous animals capture and maintain attention in humans.

PubMed

Yorzinski, Jessica L; Penkunas, Michael J; Platt, Michael L; Coss, Richard G

2014-05-28

Predation is a major source of natural selection on primates and may have shaped attentional processes that allow primates to rapidly detect dangerous animals. Because ancestral humans were subjected to predation, a process that continues at very low frequencies, we examined the visual processes by which men and women detect dangerous animals (snakes and lions). We recorded the eye movements of participants as they detected images of a dangerous animal (target) among arrays of nondangerous animals (distractors) as well as detected images of a nondangerous animal (target) among arrays of dangerous animals (distractors). We found that participants were quicker to locate targets when the targets were dangerous animals compared with nondangerous animals, even when spatial frequency and luminance were controlled. The participants were slower to locate nondangerous targets because they spent more time looking at dangerous distractors, a process known as delayed disengagement, and looked at a larger number of dangerous distractors. These results indicate that dangerous animals capture and maintain attention in humans, suggesting that historical predation has shaped some facets of visual orienting and its underlying neural architecture in modern humans.

The antibiotic resistome: gene flow in environments, animals and human beings.

PubMed

Hu, Yongfei; Gao, George F; Zhu, Baoli

2017-06-01

The antibiotic resistance is natural in bacteria and predates the human use of antibiotics. Numerous antibiotic resistance genes (ARGs) have been discovered to confer resistance to a wide range of antibiotics. The ARGs in natural environments are highly integrated and tightly regulated in specific bacterial metabolic networks. However, the antibiotic selection pressure conferred by the use of antibiotics in both human medicine and agriculture practice leads to a significant increase of antibiotic resistance and a steady accumulation of ARGs in bacteria. In this review, we summarized, with an emphasis on an ecological point of view, the important research progress regarding the collective ARGs (antibiotic resistome) in bacterial communities of natural environments, human and animals, i.e., in the one health settings.We propose that the resistance gene flow in nature is "from the natural environments" and "to the natural environments"; human and animals, as intermediate recipients and disseminators, contribute greatly to such a resistance gene "circulation."

Young children can be taught basic natural selection using a picture-storybook intervention.

PubMed

Kelemen, Deborah; Emmons, Natalie A; Seston Schillaci, Rebecca; Ganea, Patricia A

2014-04-01

Adaptation by natural selection is a core mechanism of evolution. It is also one of the most widely misunderstood scientific processes. Misconceptions are rooted in cognitive biases found in preschoolers, yet concerns about complexity mean that adaptation by natural selection is generally not comprehensively taught until adolescence. This is long after untutored theoretical misunderstandings are likely to have become entrenched. In a novel approach, we explored 5- to 8-year-olds' capacities to learn a basic but theoretically coherent mechanistic explanation of adaptation through a custom storybook intervention. Experiment 1 showed that children understood the population-based logic of natural selection and also generalized it. Furthermore, learning endured 3 months later. Experiment 2 replicated these results and showed that children understood and applied an even more nuanced mechanistic causal explanation. The findings demonstrate that, contrary to conventional educational wisdom, basic natural selection is teachable in early childhood. Theory-driven interventions using picture storybooks with rich explanatory structure are beneficial.

Getting to Darwin: Obstacles to Accepting Evolution by Natural Selection

NASA Astrophysics Data System (ADS)

Thagard, Paul; Findlay, Scott

2010-06-01

Darwin’s theory of evolution by natural selection is central to modern biology, but is resisted by many people. This paper discusses the major psychological obstacles to accepting Darwin’s theory. Cognitive obstacles to adopting evolution by natural selection include conceptual difficulties, methodological issues, and coherence problems that derive from the intuitiveness of alternative theories. The main emotional obstacles to accepting evolution are its apparent conflict with valued beliefs about God, souls, and morality. We draw on the philosophy of science and on a psychological theory of cognitive and emotional belief revision to make suggestions about what can be done to improve acceptance of Darwinian ideas.

Natural and sexual selection against immigrants maintains differentiation among micro-allopatric populations.

PubMed

Tobler, M; Riesch, R; Tobler, C M; Schulz-Mirbach, T; Plath, M

2009-11-01

Local adaptation to divergent environmental conditions can promote population genetic differentiation even in the absence of geographic barriers and hence lead to speciation. But what mechanisms contribute to reproductive isolation among diverging populations? We tested for natural and sexual selection against immigrants in a fish species inhabiting (and adapting to) nonsulphidic surface habitats, sulphidic surface habitats and a sulphidic cave. Gene flow is strong among sample sites situated within the same habitat type, but low among divergent habitat types. Our results indicate that females of both sulphidic populations discriminate against immigrant males during mate choice. Furthermore, using reciprocal translocation experiments, we document natural selection against migrants between nonsulphidic and sulphidic habitats, whereas migrants between sulphidic cave and surface habitats did not exhibit increased mortality within the same time period. Consequently, both natural and sexual selection may contribute to isolation among parapatric populations, and selection against immigrants may be a powerful mechanism facilitating speciation among locally adapted populations even over very small spatial distances.

Animal movement constraints improve resource selection inference in the presence of telemetry error

USGS Publications Warehouse

Brost, Brian M.; Hooten, Mevin B.; Hanks, Ephraim M.; Small, Robert J.

2016-01-01

Multiple factors complicate the analysis of animal telemetry location data. Recent advancements address issues such as temporal autocorrelation and telemetry measurement error, but additional challenges remain. Difficulties introduced by complicated error structures or barriers to animal movement can weaken inference. We propose an approach for obtaining resource selection inference from animal location data that accounts for complicated error structures, movement constraints, and temporally autocorrelated observations. We specify a model for telemetry data observed with error conditional on unobserved true locations that reflects prior knowledge about constraints in the animal movement process. The observed telemetry data are modeled using a flexible distribution that accommodates extreme errors and complicated error structures. Although constraints to movement are often viewed as a nuisance, we use constraints to simultaneously estimate and account for telemetry error. We apply the model to simulated data, showing that it outperforms common ad hoc approaches used when confronted with measurement error and movement constraints. We then apply our framework to an Argos satellite telemetry data set on harbor seals (Phoca vitulina) in the Gulf of Alaska, a species that is constrained to move within the marine environment and adjacent coastlines.

Natural selection on thermal preference, critical thermal maxima and locomotor performance.

PubMed

Gilbert, Anthony L; Miles, Donald B

2017-08-16

Climate change is resulting in a radical transformation of the thermal quality of habitats across the globe. Whereas species have altered their distributions to cope with changing environments, the evidence for adaptation in response to rising temperatures is limited. However, to determine the potential of adaptation in response to thermal variation, we need estimates of the magnitude and direction of natural selection on traits that are assumed to increase persistence in warmer environments. Most inferences regarding physiological adaptation are based on interspecific analyses, and those of selection on thermal traits are scarce. Here, we estimate natural selection on major thermal traits used to assess the vulnerability of ectothermic organisms to altered thermal niches. We detected significant directional selection favouring lizards with higher thermal preferences and faster sprint performance at their optimal temperature. Our analyses also revealed correlational selection between thermal preference and critical thermal maxima, where individuals that preferred warmer body temperatures with cooler critical thermal maxima were favoured by selection. Recent published estimates of heritability for thermal traits suggest that, in concert with the strong selective pressures we demonstrate here, evolutionary adaptation may promote long-term persistence of ectotherms in altered thermal environments. © 2017 The Author(s).

Natural selection on immune defense: A field experiment.

PubMed

Langeloh, Laura; Behrmann-Godel, Jasminca; Seppälä, Otto

2017-02-01

Predicting the evolution of phenotypic traits requires an understanding of natural selection on them. Despite its indispensability in the fight against parasites, selection on host immune defense has remained understudied. Theory predicts immune traits to be under stabilizing selection due to associated trade-offs with other fitness-related traits. Empirical studies, however, report mainly positive directional selection. This discrepancy could be caused by low phenotypic variation in the examined individuals and/or variation in host resource level that confounds trade-offs in empirical studies. In a field experiment where we maintained Lymnaea stagnalis snails individually in cages in a lake, we investigated phenotypic selection on two immune defense traits, phenoloxidase (PO)-like activity and antibacterial activity, in hemolymph. We used a diverse laboratory population and manipulated snail resource level by limiting their food supply. For six weeks, we followed immune activity, growth, and two fitness components, survival and fecundity of snails. We found that PO-like activity and growth were under stabilizing selection, while antibacterial activity was under positive directional selection. Selection on immune traits was mainly driven by variation in survival. The form of selection on immune defense apparently depends on the particular trait, possibly due to its importance for countering the present parasite community. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

"Everything Has to Die One Day:" Children's Explorations of the Meanings of Death in Human-Animal-Nature Relationships

ERIC Educational Resources Information Center

Russell, Joshua

2017-01-01

Children's experiences of death are a potentially vital component of their developing sense of relatedness to non-human others and nature. Environmental education theory and practice would benefit from a broader understanding of how children view death and loss within ecological systems as well as within human-animal-nature relationships, but such…

Traditional livestock breeding practices of men and women Somali pastoralists: trait preferences and selection of breeding animals.

PubMed

Marshall, K; Mtimet, N; Wanyoike, F; Ndiwa, N; Ghebremariam, H; Mugunieri, L; Costagli, R

2016-12-01

Somalia, one of the world's poorest countries, has livestock as the mainstay of the economy, with an estimated 65% of the population engaged in the livestock sector. This paper presents a gendered study on the traditional livestock breeding practices of Somali pastoralists for camels, cattle, sheep and goats, with a focus on documenting livestock traits of importance, the criteria used to select male breeding animals and the criteria used to cull female breeding animals. Data for the study were obtained by performing participatory rural appraisals (PRAs) with separate male and female pastoral groups from 20 settlements of the Tog-Dheer region of Somaliland (in north-western Somalia). In total, more than 500 pastoralists were involved. In terms of livestock ownership, goats were the most common species kept (97% of all households), followed by sheep (64%), camels (37%) and cattle (9%), with considerable herd size variation across households. Traits of key importance to the pastoralists varied by species and gender of the PRA group, but included adaptedness to harsh environmental conditions, high market value/high meat production and high milk production. The pastoralists practised sensible criteria for the selection of male breeding animals for all species, capturing aspects of productivity (milk yield, reproduction), adaptedness (good hardiness) and marketability (body size and conformation). Similarly, they practised sensible criteria for culling of female breeding animals, with females removed from the herd primarily for poor performance, but also to meet the livelihood needs of the family. Differences in the selection and culling criteria were noted by species, as well as gender of the pastoralists. On the whole, there was strong alignment between the livestock selection criteria used by the Somali pastoralists, their reasons for keeping livestock and the market requirements. This is not surprising given the intimate and long-standing relationship between Somali

Antagonistic responses to natural and sexual selection and the sex-specific evolution of cuticular hydrocarbons in Drosophila simulans.

PubMed

Sharma, Manmohan D; Hunt, John; Hosken, David J

2012-03-01

Natural and sexual selection are classically thought to oppose one another, and although there is evidence for this, direct experimental demonstrations of this antagonism are largely lacking. Here, we assessed the effects of sexual and natural selection on the evolution of cuticular hydrocarbons (CHCs), a character subject to both modes of selection, in Drosophila simulans. Natural selection and sexual selection were manipulated in a fully factorial design, and after 27 generations of experimental evolution, the responses of male and female CHCs were assessed. The effects of natural and sexual selection differed greatly across the sexes. The responses of female CHCs were generally small, but CHCs evolved predominantly in the direction of natural selection. For males, profiles evolved via sexual and natural selection, as well as through the interaction between the two, with some male CHC components only evolving in the direction of natural selection when sexual selection was relaxed. These results indicate sex-specific responses to selection, and that sexual and natural selection act antagonistically for at least some combinations of CHCs. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Natural selection on thermal performance in a novel thermal environment

PubMed Central

Logan, Michael L.; Cox, Robert M.; Calsbeek, Ryan

2014-01-01

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation to changing conditions. Here, we mimic the effects of climate change by experimentally transplanting a population of Anolis sagrei lizards to a novel thermal environment. Transplanted lizards experienced warmer and more thermally variable conditions, which resulted in strong directional selection on thermal performance traits. These same traits were not under selection in a reference population studied in a less thermally stressful environment. Our results indicate that climate change can exert strong natural selection on tropical ectotherms, despite their ability to thermoregulate behaviorally. To the extent that thermal performance traits are heritable, populations may be capable of rapid adaptation to anthropogenic warming. PMID:25225361

Natural selection on thermal performance in a novel thermal environment.

PubMed

Logan, Michael L; Cox, Robert M; Calsbeek, Ryan

2014-09-30

Tropical ectotherms are thought to be especially vulnerable to climate change because they are adapted to relatively stable temperature regimes, such that even small increases in environmental temperature may lead to large decreases in physiological performance. One way in which tropical organisms may mitigate the detrimental effects of warming is through evolutionary change in thermal physiology. The speed and magnitude of this response depend, in part, on the strength of climate-driven selection. However, many ectotherms use behavioral adjustments to maintain preferred body temperatures in the face of environmental variation. These behaviors may shelter individuals from natural selection, preventing evolutionary adaptation to changing conditions. Here, we mimic the effects of climate change by experimentally transplanting a population of Anolis sagrei lizards to a novel thermal environment. Transplanted lizards experienced warmer and more thermally variable conditions, which resulted in strong directional selection on thermal performance traits. These same traits were not under selection in a reference population studied in a less thermally stressful environment. Our results indicate that climate change can exert strong natural selection on tropical ectotherms, despite their ability to thermoregulate behaviorally. To the extent that thermal performance traits are heritable, populations may be capable of rapid adaptation to anthropogenic warming.

Birth-order differences can drive natural selection on aging.

PubMed

Gillespie, Duncan O S; Trotter, Meredith V; Krishna-Kumar, Siddharth; Tuljapurkar, Shripad D

2014-03-01

Senescence-the deterioration of survival and reproductive capacity with increasing age-is generally held to be an evolutionary consequence of the declining strength of natural selection with increasing age. The diversity in rates of aging observed in nature suggests that the rate at which age-specific selection weakens is determined by species-specific ecological factors. We propose that, in iteroparous species, relationships between parental age, offspring birth order, and environment may affect selection on senescence. Later-born siblings have, on average, older parents than do first borns. Offspring born to older parents may experience different environments in terms of family support or inherited resources, factors often mediated by competition from siblings. Thus, age-specific selection on parents may change if the environment produces birth-order related gradients in reproductive success. We use an age-and-stage structured population model to investigate the impact of sibling environmental inequality on the expected evolution of senescence. We show that accelerated senescence evolves when later-born siblings are likely to experience an environment detrimental to lifetime reproduction. In general, sibling inequality is likely to be of particular importance for the evolution of senescence in species such as humans, where family interactions and resource inheritance have important roles in determining lifetime reproduction. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Animal responses to natural disturbance and climate extremes: a review

NASA Astrophysics Data System (ADS)

Sergio, Fabrizio; Blas, Julio; Hiraldo, Fernando

2018-02-01

Natural disturbances, such as droughts, fires or hurricanes, are key drivers of ecological heterogeneity and ecosystem function. The frequency and severity of these episodes is unequivocally expected to increase in the coming decades, through the concerted action of climate change and anthropogenic pressures. This will impose severe challenges for many biota through exposure to rapidly changing conditions never experienced in the preceding millennia. Thus, it is urgently needed to gain a thorough understanding of animal responses and adaptations to disturbances in order to better estimate potential future impacts. Here, we review such adjustments and find that animals may respond to disturbances through changes in: (1) behaviour, such as altered mobility, emigration, resource-switching, refuge use, suspended animation, or biotic interactions; (2) life history traits, such as survival, aging, longevity, recruitment, reproductive restraint, breeding output, phenology and bet-hedging tactics; (3) morphology, such as rapid evolution through size-dependent mortality or facultative metamorphosis; (4) physiology, such as altered body condition, pathogen prevalence and transmission, or adrenocortical modulation of stress responses to emergency conditions; (5) genetic structure, such as changes in frequency of polymorphic variants or diversity-modulation through mortality bottlenecks. Individual-level responses scale up to population and community responses, such as altered density, population dynamics, distribution, local extinction and colonization, or assemblage structure and diversity. Overall, disturbances have pervasive effects on individuals, populations and communities of vertebrates and invertebrates of all realms, biomes, continents and ecosystems. Their rapidly increasing incidence and severity will bring unique study opportunities for researchers and novel, unpredictable challenges for managers, while demanding tougher choices and more proactive crisis

Elementary Students' Investigations in Natural Selection

ERIC Educational Resources Information Center

Bartley, Nancy; Concannon, James P.; Brown, Patrick L.

2014-01-01

Students love learning about animals: how animals behave, what animals eat, why some animals are more dangerous than others are, and why animals look the way they do. In this 5E lesson, students investigate why some animals look the way they do--specifically, the advantages of camouflage and mimicry. What are an animal's advantages of being…

Nonconsumptive predator-driven mortality causes natural selection on prey.

PubMed

Siepielski, Adam M; Wang, Jason; Prince, Garrett

2014-03-01

Predators frequently exert natural selection through differential consumption of their prey. However, predators may also cause prey mortality through nonconsumptive effects, which could cause selection if different prey phenotypes are differentially susceptible to this nonconsumptive mortality. Here we present an experimental test of this hypothesis, which reveals that nonconsumptive mortality imposed by predatory dragonflies causes selection on their damselfly prey favoring increased activity levels. These results are consistent with other studies of predator-driven selection, however, they reveal that consumption alone is not the only mechanism by which predators can exert selection on prey. Uncovering this mechanism also suggests that prey defensive traits may represent adaptations to not only avoid being consumed, but also for dealing with other sources of mortality caused by predators. Demonstrating selection through both consumptive and nonconsumptive predator mortality provides us with insight into the diverse effects of predators as an evolutionary force. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Target-Selectivity of Parvalbumin-Positive Interneurons in Layer II of Medial Entorhinal Cortex in Normal and Epileptic Animals

PubMed Central

Armstrong, Caren; Wang, Jessica; Lee, Soo Yeun; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2015-01-01

The medial entorhinal cortex layer II (MEClayerII) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII. However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII. However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII. Taken together, these findings advance our

Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.

PubMed

Armstrong, Caren; Wang, Jessica; Yeun Lee, Soo; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2016-06-01

The medial entorhinal cortex layer II (MEClayerII ) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII . However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII . However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII . Taken together, these findings advance

Fantastic animals as an experimental model to teach animal adaptation

PubMed Central

Guidetti, Roberto; Baraldi, Laura; Calzolai, Caterina; Pini, Lorenza; Veronesi, Paola; Pederzoli, Aurora

2007-01-01

Background Science curricula and teachers should emphasize evolution in a manner commensurate with its importance as a unifying concept in science. The concept of adaptation represents a first step to understand the results of natural selection. We settled an experimental project of alternative didactic to improve knowledge of organism adaptation. Students were involved and stimulated in learning processes by creative activities. To set adaptation in a historic frame, fossil records as evidence of past life and evolution were considered. Results The experimental project is schematized in nine phases: review of previous knowledge; lesson on fossils; lesson on fantastic animals; planning an imaginary world; creation of an imaginary animal; revision of the imaginary animals; adaptations of real animals; adaptations of fossil animals; and public exposition. A rubric to evaluate the student's performances is reported. The project involved professors and students of the University of Modena and Reggio Emilia and of the "G. Marconi" Secondary School of First Degree (Modena, Italy). Conclusion The educational objectives of the project are in line with the National Indications of the Italian Ministry of Public Instruction: knowledge of the characteristics of living beings, the meanings of the term "adaptation", the meaning of fossils, the definition of ecosystem, and the particularity of the different biomes. At the end of the project, students will be able to grasp particular adaptations of real organisms and to deduce information about the environment in which the organism evolved. This project allows students to review previous knowledge and to form their personalities. PMID:17767729

The basic science and mathematics of random mutation and natural selection.

PubMed

Kleinman, Alan

2014-12-20

The mutation and natural selection phenomenon can and often does cause the failure of antimicrobial, herbicidal, pesticide and cancer treatments selection pressures. This phenomenon operates in a mathematically predictable behavior, which when understood leads to approaches to reduce and prevent the failure of the use of these selection pressures. The mathematical behavior of mutation and selection is derived using the principles given by probability theory. The derivation of the equations describing the mutation and selection phenomenon is carried out in the context of an empirical example. Copyright © 2014 John Wiley & Sons, Ltd.

Pollinators exert natural selection on flower size and floral display in Penstemon digitalis.

PubMed

Parachnowitsch, Amy L; Kessler, André

2010-10-01

• A major gap in our understanding of floral evolution, especially micro-evolutionary processes, is the role of pollinators in generating patterns of natural selection on floral traits. Here we explicitly tested the role of pollinators in selecting floral traits in a herbaceous perennial, Penstemon digitalis. • We manipulated the effect of pollinators on fitness through hand pollinations and compared phenotypic selection in open- and hand-pollinated plants. • Despite the lack of pollen limitation in our population, pollinators mediated selection on floral size and floral display. Hand pollinations removed directional selection for larger flowers and stabilizing selection on flower number, suggesting that pollinators were the agents of selection on both of these traits. • We reviewed studies that measured natural selection on floral traits by biotic agents and generally found stronger signatures of selection imposed by pollinators than by herbivores and co-flowering plant species. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Image statistics underlying natural texture selectivity of neurons in macaque V4

PubMed Central

Okazawa, Gouki; Tajima, Satohiro; Komatsu, Hidehiko

2015-01-01

Our daily visual experiences are inevitably linked to recognizing the rich variety of textures. However, how the brain encodes and differentiates a plethora of natural textures remains poorly understood. Here, we show that many neurons in macaque V4 selectively encode sparse combinations of higher-order image statistics to represent natural textures. We systematically explored neural selectivity in a high-dimensional texture space by combining texture synthesis and efficient-sampling techniques. This yielded parameterized models for individual texture-selective neurons. The models provided parsimonious but powerful predictors for each neuron’s preferred textures using a sparse combination of image statistics. As a whole population, the neuronal tuning was distributed in a way suitable for categorizing textures and quantitatively predicts human ability to discriminate textures. Together, we suggest that the collective representation of visual image statistics in V4 plays a key role in organizing the natural texture perception. PMID:25535362

Differential Visual Processing of Animal Images, with and without Conscious Awareness

PubMed Central

Zhu, Weina; Drewes, Jan; Peatfield, Nicholas A.; Melcher, David

2016-01-01

The human visual system can quickly and efficiently extract categorical information from a complex natural scene. The rapid detection of animals in a scene is one compelling example of this phenomenon, and it suggests the automatic processing of at least some types of categories with little or no attentional requirements (Li et al., 2002, 2005). The aim of this study is to investigate whether the remarkable capability to categorize complex natural scenes exist in the absence of awareness, based on recent reports that “invisible” stimuli, which do not reach conscious awareness, can still be processed by the human visual system (Pasley et al., 2004; Williams et al., 2004; Fang and He, 2005; Jiang et al., 2006, 2007; Kaunitz et al., 2011a). In two experiments, we recorded event-related potentials (ERPs) in response to animal and non-animal/vehicle stimuli in both aware and unaware conditions in a continuous flash suppression (CFS) paradigm. Our results indicate that even in the “unseen” condition, the brain responds differently to animal and non-animal/vehicle images, consistent with rapid activation of animal-selective feature detectors prior to, or outside of, suppression by the CFS mask. PMID:27790106

Differential Visual Processing of Animal Images, with and without Conscious Awareness.

PubMed

Zhu, Weina; Drewes, Jan; Peatfield, Nicholas A; Melcher, David

2016-01-01

The human visual system can quickly and efficiently extract categorical information from a complex natural scene. The rapid detection of animals in a scene is one compelling example of this phenomenon, and it suggests the automatic processing of at least some types of categories with little or no attentional requirements (Li et al., 2002, 2005). The aim of this study is to investigate whether the remarkable capability to categorize complex natural scenes exist in the absence of awareness, based on recent reports that "invisible" stimuli, which do not reach conscious awareness, can still be processed by the human visual system (Pasley et al., 2004; Williams et al., 2004; Fang and He, 2005; Jiang et al., 2006, 2007; Kaunitz et al., 2011a). In two experiments, we recorded event-related potentials (ERPs) in response to animal and non-animal/vehicle stimuli in both aware and unaware conditions in a continuous flash suppression (CFS) paradigm. Our results indicate that even in the "unseen" condition, the brain responds differently to animal and non-animal/vehicle images, consistent with rapid activation of animal-selective feature detectors prior to, or outside of, suppression by the CFS mask.

Widespread Natural Occurrence of Hydroxyurea in Animals.

PubMed

Fraser, David I; Liu, Kyle T; Reid, Bryan J; Hawkins, Emily; Sevier, Andrew; Pyle, Michelle; Robinson, Jacob W; Ouellette, Pierre H R; Ballantyne, James S

2015-01-01

Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics.

Widespread Natural Occurrence of Hydroxyurea in Animals

PubMed Central

Fraser, David I.; Liu, Kyle T.; Reid, Bryan J.; Hawkins, Emily; Sevier, Andrew; Pyle, Michelle; Robinson, Jacob W.; Ouellette, Pierre H. R.; Ballantyne, James S.

2015-01-01

Here we report the widespread natural occurrence of a known antibiotic and antineoplastic compound, hydroxyurea in animals from many taxonomic groups. Hydroxyurea occurs in all the organisms we have examined including invertebrates (molluscs and crustaceans), fishes from several major groups, amphibians and mammals. The species with highest concentrations was an elasmobranch (sharks, skates and rays), the little skate Leucoraja erinacea with levels up to 250 μM, high enough to have antiviral, antimicrobial and antineoplastic effects based on in vitro studies. Embryos of L. erinacea showed increasing levels of hydroxyurea with development, indicating the capacity for hydroxyurea synthesis. Certain tissues of other organisms (e.g. skin of the frog (64 μM), intestine of lobster (138 μM) gills of the surf clam (100 μM)) had levels high enough to have antiviral effects based on in vitro studies. Hydroxyurea is widely used clinically in the treatment of certain human cancers, sickle cell anemia, psoriasis, myeloproliferative diseases, and has been investigated as a potential treatment of HIV infection and its presence at high levels in tissues of elasmobranchs and other organisms suggests a novel mechanism for fighting disease that may explain the disease resistance of some groups. In light of the known production of nitric oxide from exogenously applied hydroxyurea, endogenous hydoxyurea may play a hitherto unknown role in nitric oxide dynamics. PMID:26600157

[Vancomycin-resistant enterococci - the nature of resistance and risk of transmission from animals to humans].

PubMed

Hermanovská, Lýdia; Bardoň, Jan; Čermák, Pavel

2016-06-01

Enterococci are part of the normal intestinal flora of humans and animals. Under certain circumstances, they are capable of extraintestinal conversion to opportunistic pathogens. They cause endogenous as well as exogenous community and nosocomial infections. The gastrointestinal tract of mammals provides them with favorable conditions for acquisition and spread of resistance genes, for example to vancomycin (van), from other symbiotic bacteria. Thus, vancomycin-resistant enterococci (VRE) become potential reservoirs and vectors of the van genes. Their occurrence in the population of the Czech Republic was first reported by Kolář et al. in 1997. Some variants of the vanA gene cluster carried on Tn1546 which encode resistance to vancomycin are identical in humans and in animals. It means that animals, especially cattle, poultry and pigs, could be an important reservoir of VRE for humans. Kolář and Bardoň detected VRE in animals in the Czech Republic for the first time in 2000. In Europe, the glycopeptide antibiotic avoparcin, used as a growth stimulator, is responsible for selection of VRE strains in animals. Strains of Enterococcus faecium from animals may offer genes of antimicrobial resistance to other enterococci or they can be directly dangerous to human. This is demonstrated by finding isolates of E. faecalis from human patients and from pigs having very similar profiles of resistance and virulence genes. The goal of the paper was to point out the similarity between isolates of human and animal strains of enterococci resistant to vancomycin, and the possibility of their bilateral transfer between humans and animals.

All about Animal Adaptations. Animal Life for Children. [Videotape].

ERIC Educational Resources Information Center

2000

Animals change to better adapt to their environment. Over long periods of time, nature helps the animals adapt by changing their body shape and color as well as adjusting their methods of getting and eating food, defending themselves, and caring for their young. In this videotape, students learn what changes different animals go through in order…

The Unit of Natural Selection: Groups, Families, Individuals, or Genes?

ERIC Educational Resources Information Center

Reiss, Michael J.

1985-01-01

Offers perspectives on natural selection and the phenomenon of altruism. Presents evidence for and against the theories that evolution acts essentially on genes, on individuals, on kin, or on larger groups. (ML)

Natural Selection Is a Sorting Process: What Does that Mean?

ERIC Educational Resources Information Center

Price, Rebecca M.

2013-01-01

To learn why natural selection acts only on existing variation, students categorize processes as either creative or sorting. This activity helps students confront the misconception that adaptations evolve because species need them.

Animal selection for whole genome sequencing by quantifying the unique contribution of homozygous haplotypes sequenced

USDA-ARS?s Scientific Manuscript database

Major whole genome sequencing projects promise to identify rare and causal variants within livestock species; however, the efficient selection of animals for sequencing remains a major problem within these surveys. The goal of this project was to develop a library of high accuracy genetic variants f...

How could it be? calling for science curricula that cultivate morals and values towards other animals and nature

NASA Astrophysics Data System (ADS)

Logan, Marianne R.; Russell, Joshua J.

2016-12-01

Can science curricula truly cultivate morals and values towards nature? This is the question that is raised by Carolina Castano Rodriguez in her critique of the new Australian Science curriculum. In this response to Castano Rodriguez's paper we ask two questions relating to: the influence of curricula on the relationships of children and other animals; and other models of science education regarding animals and nature that may be more relevant, just, or caring. In responding to these questions stimulated by the reading of Castano Rodriguez's paper, we reflect on our own experiences. We note the conflict between the values depicted in the curriculum priorities and the underlying anthropocentric view that appears to be embedded in the Australian Science Curriculum and in curricula generally. With this conflict in mind we encourage educators to examine our own practices regarding how the relationships between humans and other animals are promoted. We put forward the idea of science education that responds to the shifting views of science and its applications outside the confines of the laboratory to one that encourages both ethical and political discussion that is already taking place in the community relating to the role of science and technology in our lives and the lives of other animals.

Global genetic differentiation of complex traits shaped by natural selection in humans.

PubMed

Guo, Jing; Wu, Yang; Zhu, Zhihong; Zheng, Zhili; Trzaskowski, Maciej; Zeng, Jian; Robinson, Matthew R; Visscher, Peter M; Yang, Jian

2018-05-14

There are mean differences in complex traits among global human populations. We hypothesize that part of the phenotypic differentiation is due to natural selection. To address this hypothesis, we assess the differentiation in allele frequencies of trait-associated SNPs among African, Eastern Asian, and European populations for ten complex traits using data of large sample size (up to ~405,000). We show that SNPs associated with height ([Formula: see text]), waist-to-hip ratio ([Formula: see text]), and schizophrenia ([Formula: see text]) are significantly more differentiated among populations than matched "control" SNPs, suggesting that these trait-associated SNPs have undergone natural selection. We further find that SNPs associated with height ([Formula: see text]) and schizophrenia ([Formula: see text]) show significantly higher variance in linkage disequilibrium (LD) scores across populations than control SNPs. Our results support the hypothesis that natural selection has shaped the genetic differentiation of complex traits, such as height and schizophrenia, among worldwide populations.

The Emergence of Physiology and Form: Natural Selection Revisited

PubMed Central

Torday, John S.

2016-01-01

Natural Selection describes how species have evolved differentially, but it is descriptive, non-mechanistic. What mechanisms does Nature use to accomplish this feat? One known way in which ancient natural forces affect development, phylogeny and physiology is through gravitational effects that have evolved as mechanotransduction, seen in the lung, kidney and bone, linking as molecular homologies to skin and brain. Tracing the ontogenetic and phylogenetic changes that have facilitated mechanotransduction identifies specific homologous cell-types and functional molecular markers for lung homeostasis that reveal how and why complex physiologic traits have evolved from the unicellular to the multicellular state. Such data are reinforced by their reverse-evolutionary patterns in chronic degenerative diseases. The physiologic responses of model organisms like Dictyostelium and yeast to gravity provide deep comparative molecular phenotypic homologies, revealing mammalian Target of Rapamycin (mTOR) as the final common pathway for vertical integration of vertebrate physiologic evolution; mTOR integrates calcium/lipid epistatic balance as both the proximate and ultimate positive selection pressure for vertebrate physiologic evolution. The commonality of all vertebrate structure-function relationships can be reduced to calcium/lipid homeostatic regulation as the fractal unit of vertebrate physiology, demonstrating the primacy of the unicellular state as the fundament of physiologic evolution. PMID:27534726

Student concepts of Natural Selection from a resource-based perspective

NASA Astrophysics Data System (ADS)

Benjamin, Scott Shawn

The past two decades have produced a substantial amount of research about the teaching and learning of evolution; however, recent research often lacks a theoretical foundation. Application of a new theoretical framework could help fill the void and improve research about student concepts of evolution. This study seeks to show that a resource-based framework (Hammer et al., 2005) can improve research into student concepts of natural selection. Concepts of natural selection from urban community college students were assessed via qualitative (interviews, written open-response questions, and write/think aloud procedures) and quantitative methods (coded open response analysis, Concept Inventory for Natural Selection (CINS)(Anderson, Fisher, & Norman, 2002). Results showed that students demonstrate four important aspects of resource-based framework: the multi-faceted construction of concepts, context sensitivity/ concept flexibility, at-the-moment activation of resources, and perceptual frames. In open response assessment, evolutionary-gain responses produced significantly different responses than evolutionary-loss questions with: 1) significantly more correct answers for the gain than loss question (Wilcoxon signed rank test, z = -3.68, p=0.0002); 2) more Lamarckian responses to loss than the gain question (Fisher exact, p=0.0039); and significantly different distributions in expanded need vs basic need answers (Fishers exact, p = 0.02). Results from CINS scores showed significant differences in post activity scores between students that held different naive concepts associated with origin of variation, origin of species, differential reproduction, and limited survival suggesting that some naive ideas facilitate learning. Outcomes also suggest that an everyday or self-experience typological perceptual frame is an underlying source of many incorrect ideas about evolution. Interview and write/think aloud assessments propose four process resources applied by students as

Using Different Examples of Natural Selection When Teaching Biology.

ERIC Educational Resources Information Center

Perry, Robert T.

1993-01-01

Describes the following examples of natural selection for use in science instruction: sickle-cell anemia and human beings, clogged crabs, the rounding of the human head, shell color in land snails, pollinator behavior and flower color, copper tolerance in a grass, lizards and quick change, and Darwin's finches. (PR)

The Living Dead: Transformative Experiences in Modelling Natural Selection

ERIC Educational Resources Information Center

Petersen, Morten Rask

2017-01-01

This study considers how students change their coherent conceptual understanding of natural selection through a hands-on simulation. The results show that most students change their understanding. In addition, some students also underwent a transformative experience and used their new knowledge in a leisure time activity. These transformative…

A systems approach to animal communication

PubMed Central

Barron, Andrew B.; Balakrishnan, Christopher N.; Hauber, Mark E.; Hoke, Kim L.

2016-01-01

Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication—an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex. PMID:26936240

A systems approach to animal communication.

PubMed

Hebets, Eileen A; Barron, Andrew B; Balakrishnan, Christopher N; Hauber, Mark E; Mason, Paul H; Hoke, Kim L

2016-03-16

Why animal communication displays are so complex and how they have evolved are active foci of research with a long and rich history. Progress towards an evolutionary analysis of signal complexity, however, has been constrained by a lack of hypotheses to explain similarities and/or differences in signalling systems across taxa. To address this, we advocate incorporating a systems approach into studies of animal communication--an approach that includes comprehensive experimental designs and data collection in combination with the implementation of systems concepts and tools. A systems approach evaluates overall display architecture, including how components interact to alter function, and how function varies in different states of the system. We provide a brief overview of the current state of the field, including a focus on select studies that highlight the dynamic nature of animal signalling. We then introduce core concepts from systems biology (redundancy, degeneracy, pluripotentiality, and modularity) and discuss their relationships with system properties (e.g. robustness, flexibility, evolvability). We translate systems concepts into an animal communication framework and accentuate their utility through a case study. Finally, we demonstrate how consideration of the system-level organization of animal communication poses new practical research questions that will aid our understanding of how and why animal displays are so complex. © 2016 The Author(s).

Change in genetic correlation due to selection using animal model evaluation.

PubMed

Strandén, I; Mäntysaari, E A; Mäki-Tanila, A

1993-01-12

Monte Carlo simulation and analytical calculations were used to study the effect of selection on genetic correlation between two traits. The simulated breeding program was based on a closed adult multiple ovulation and embryo transfer nucleus breeding scheme. Selection was on an index calculated using multi-trait animal model (AM). Analytical formulae applicable to any evaluation method were derived to predict change in genetic (co)variance due to selection under multi-trait selection using different evaluation methods. Two formulae were investigated, one assuming phenotypic selection and the other based on a recursive two-generation AM selection index. The recursive AM method approximated information due to relatives by a relationship matrix of two generations. Genetic correlation after selection was compared under different levels of initial genetic and environmental correlations with two different selection criteria. Changes in genetic correlation were similar in simulation and analytical predictions. After one round of selection the recursive AM method and the simulation gave similar predictions while the phenotypic selection predicted usually more change in genetic correlation. After several rounds of selection both analytical formulae predicted more change in genetic correlation than the simulation. ZUSAMMENFASSUNG: Änderung der genetischen Korrelation bei Selektion mit einem Tiermodell Der Selektionseffekt auf die genetische Korrelation zwischen zwei Merkmalen wurde mit Hilfe von Monte Carlo-Simulation und analytischen Berechnungen untersucht. Ein geschlossener Adulter - MOET (Multiple Ovulation and Embryo Transfer) Zuchtplan wurde simuliert. Die Selektion gründete sich auf einen Index, der die Zuchtwertschätzung des Mehrmerkmals-Tiermodells benutzte. Analytische Formeln für die Voraussage der Änderung der genetischen (Ko)varianz unter multivariate Selektion für verschiedene Zuchtwertschätzungsmethode wurden deduziert. Zwei Formeln wurden studiert

Senescence in natural populations of animals: Widespread evidence and its implications for bio-gerontology

PubMed Central

Nussey, Daniel H.; Froy, Hannah; Lemaitre, Jean-François; Gaillard, Jean-Michel; Austad, Steve N.

2014-01-01

That senescence is rarely, if ever, observed in natural populations is an oft-quoted fallacy within bio-gerontology. We identify the roots of this fallacy in the otherwise seminal works of Medawar and Comfort, and explain that under antagonistic pleiotropy or disposable soma explanations for the evolution of senescence there is no reason why senescence cannot evolve to be manifest within the life expectancies of wild organisms. The recent emergence of long-term field studies presents irrefutable evidence that senescence is commonly detected in nature. We found such evidence in 175 different animal species from 340 separate studies. Although the bulk of this evidence comes from birds and mammals, we also found evidence for senescence in other vertebrates and insects. We describe how high-quality longitudinal field data allow us to test evolutionary explanations for differences in senescence between the sexes and among traits and individuals. Recent studies indicate that genes, prior environment and investment in growth and reproduction influence aging rates in the wild. We argue that – with the fallacy that wild animals do not senesce finally dead and buried – collaborations between bio-gerontologists and field biologists can begin to test the ecological generality of purportedly ‘public’ mechanisms regulating aging in laboratory models. PMID:22884974

Frugivore-Mediated Selection in A Habitat Transformation Scenario

PubMed Central

Fontúrbel, Francisco E.; Medel, Rodrigo

2017-01-01

Plant-animal interactions are strong drivers of phenotypic evolution. However, the extent to which anthropogenic habitat transformation creates new selective scenarios for plant-animal interactions is a little explored subject. We examined the effects of native forest replacement by exotic Eucalyptus trees on the frugivore-mediated phenotypic selection coefficients imposed by the relict marsupial Dromiciops gliroides upon traits involved in frugivore attraction and germination success of the mistletoe Tristerix corymbosus (Loranthaceae). We found significant gradients for seed weight and sugar content along the native - transformed habitat gradient. While selection for larger seed weight was more relevant in native habitats, fruits with intermediate sugar content were promoted in transformed habitats. The spatial habitat structure and microclimate features such as the degree of sunlight received influenced the natural selection processes, as they correlated with the phenotypic traits analysed. The response of this plant-frugivore interaction to human disturbance seemed to be context-dependent, in which extremely transformed habitats would offer new opportunities for natural selection on dispersal-related traits. Even in recent transformation events like this, human disturbance acts as a strong contemporary evolution driver. PMID:28349942

Clonality, genetic diversity and support for the diversifying selection hypothesis in natural populations of a flower-living yeast.

PubMed

Herrera, C M; Pozo, M I; Bazaga, P

2011-11-01

Vast amounts of effort have been devoted to investigate patterns of genetic diversity and structuring in plants and animals, but similar information is scarce for organisms of other kingdoms. The study of the genetic structure of natural populations of wild yeasts can provide insights into the ecological and genetic correlates of clonality, and into the generality of recent hypotheses postulating that microbial populations lack the potential for genetic divergence and allopatric speciation. Ninety-one isolates of the flower-living yeast Metschnikowia gruessii from southeastern Spain were DNA fingerprinted using amplified fragment length polymorphism (AFLP) markers. Genetic diversity and structuring was investigated with band-based methods and model- and nonmodel-based clustering. Linkage disequilibrium tests were used to assess reproduction mode. Microsite-dependent, diversifying selection was tested by comparing genetic characteristics of isolates from bumble bee vectors and different floral microsites. AFLP polymorphism (91%) and genotypic diversity were very high. Genetic diversity was spatially structured, as shown by amova (Φ(st)  = 0.155) and clustering. The null hypothesis of random mating was rejected, clonality seeming the prevailing reproductive mode in the populations studied. Genetic diversity of isolates declined from bumble bee mouthparts to floral microsites, and frequency of five AFLP markers varied significantly across floral microsites, thus supporting the hypothesis of diversifying selection on clonal lineages. Wild populations of clonal fungal microbes can exhibit levels of genetic diversity and spatial structuring that are not singularly different from those shown by sexually reproducing plants or animals. Microsite-dependent, divergent selection can maintain high local and regional genetic diversity in microbial populations despite extensive clonality. © 2011 Blackwell Publishing Ltd.

Companion Animals, Natural Disasters and the Law: An Australian Perspective.

PubMed

White, Steven

2012-08-27

This article examines the regulation of companion animal welfare during disasters, with some context provided by two recent major disaster events in Australia. Important general lessons for improved disaster management were identified in subsequent inquiries. However, the interests of companion animals continue to be inadequately addressed. This is because key assumptions underpinning disaster planning for companion animals-the primacy of human interests over animal interests and that individuals will properly address companion animal needs during times of disaster-are open to question. In particular these assumptions fail to recognise the inherent value of companion animals, underestimate the strong bond shared by some owners and their animals and, at the same time, overestimate the capacity of some owners to adequately meet the needs of their animals.

Edge co-occurrences can account for rapid categorization of natural versus animal images

NASA Astrophysics Data System (ADS)

Perrinet, Laurent U.; Bednar, James A.

2015-06-01

Making a judgment about the semantic category of a visual scene, such as whether it contains an animal, is typically assumed to involve high-level associative brain areas. Previous explanations require progressively analyzing the scene hierarchically at increasing levels of abstraction, from edge extraction to mid-level object recognition and then object categorization. Here we show that the statistics of edge co-occurrences alone are sufficient to perform a rough yet robust (translation, scale, and rotation invariant) scene categorization. We first extracted the edges from images using a scale-space analysis coupled with a sparse coding algorithm. We then computed the “association field” for different categories (natural, man-made, or containing an animal) by computing the statistics of edge co-occurrences. These differed strongly, with animal images having more curved configurations. We show that this geometry alone is sufficient for categorization, and that the pattern of errors made by humans is consistent with this procedure. Because these statistics could be measured as early as the primary visual cortex, the results challenge widely held assumptions about the flow of computations in the visual system. The results also suggest new algorithms for image classification and signal processing that exploit correlations between low-level structure and the underlying semantic category.

The Neural Dynamics of Attentional Selection in Natural Scenes.

PubMed

Kaiser, Daniel; Oosterhof, Nikolaas N; Peelen, Marius V

2016-10-12

The human visual system can only represent a small subset of the many objects present in cluttered scenes at any given time, such that objects compete for representation. Despite these processing limitations, the detection of object categories in cluttered natural scenes is remarkably rapid. How does the brain efficiently select goal-relevant objects from cluttered scenes? In the present study, we used multivariate decoding of magneto-encephalography (MEG) data to track the neural representation of within-scene objects as a function of top-down attentional set. Participants detected categorical targets (cars or people) in natural scenes. The presence of these categories within a scene was decoded from MEG sensor patterns by training linear classifiers on differentiating cars and people in isolation and testing these classifiers on scenes containing one of the two categories. The presence of a specific category in a scene could be reliably decoded from MEG response patterns as early as 160 ms, despite substantial scene clutter and variation in the visual appearance of each category. Strikingly, we find that these early categorical representations fully depend on the match between visual input and top-down attentional set: only objects that matched the current attentional set were processed to the category level within the first 200 ms after scene onset. A sensor-space searchlight analysis revealed that this early attention bias was localized to lateral occipitotemporal cortex, reflecting top-down modulation of visual processing. These results show that attention quickly resolves competition between objects in cluttered natural scenes, allowing for the rapid neural representation of goal-relevant objects. Efficient attentional selection is crucial in many everyday situations. For example, when driving a car, we need to quickly detect obstacles, such as pedestrians crossing the street, while ignoring irrelevant objects. How can humans efficiently perform such tasks

A Conceptual Characterization of Online Videos Explaining Natural Selection

ERIC Educational Resources Information Center

Bohlin, Gustav; Göransson, Andreas; Höst, Gunnar E.; Tibell, Lena A. E.

2017-01-01

Educational videos on the Internet comprise a vast and highly diverse source of information. Online search engines facilitate access to numerous videos claiming to explain natural selection, but little is known about the degree to which the video content match key evolutionary content identified as important in evolution education research. In…

Animal rights and animal experimentation. Implications for physicians.

PubMed Central

Gelpi, A. P.

1991-01-01

Practicing physicians are just becoming aware of the animal rights movement, which during the 1980s spawned numerous acts of violence against research facilities throughout the United States. The animal rightists are challenging physicians to show moral justification for the human exploitation of nature and the world of subhuman species. They have aroused public interest in animal welfare, sparked protective legislation for experimental animals, and indirectly encouraged the creation of committees to oversee the conduct of animal experimentation and the conditions of animal confinement. This controversy has necessitated a closer look at the questions of animal experimentation and animal rights against the backdrop of human experimentation and human rights. Physicians and specialists in animal care seek to alleviate suffering and anxiety, and, as moderates, they may be able to bring both sides of the animal rights controversy together in a spirit of mutual tolerance and in the common cause of promoting both human and animal welfare. PMID:1949772

Taming the Past: Ancient DNA and the Study of Animal Domestication.

PubMed

MacHugh, David E; Larson, Greger; Orlando, Ludovic

2017-02-08

During the last decade, ancient DNA research has been revolutionized by the availability of increasingly powerful DNA sequencing and ancillary genomics technologies, giving rise to the new field of paleogenomics. In this review, we show how our understanding of the genetic basis of animal domestication and the origins and dispersal of livestock and companion animals during the Upper Paleolithic and Neolithic periods is being rapidly transformed through new scientific knowledge generated with paleogenomic methods. These techniques have been particularly informative in revealing high-resolution patterns of artificial and natural selection and evidence for significant admixture between early domestic animal populations and their wild congeners.

Naturally seeded versus planted ponderosa pine seedlings in group-selection openings

Treesearch

Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson

2009-01-01

The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer dependson the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In thisside-by-side study, the natural pine seedlings originated...

Body Size Preference of Marine Animals in Relation to Extinction Selectivity

NASA Astrophysics Data System (ADS)

Sriram, A.; Idgunji, S.; Heim, N. A.; Payne, J.

2014-12-01

Our project encompasses an extremely specific aspect in relation to the five mass extinctions in geologic history. We asked ourselves whether larger or smaller body sizes would be better suited for surviving a mass extinction. To conduct research for our project, we used the body sizes of 17,172 marine animal genera as our primary data. These animals include echinoderms, arthropods, chordates, mollusks, and brachiopods. These creatures are perfect model organisms in terms of finding data on them because they have an excellent fossil record, and are well documented. We focused on the mean body size of these animals before and after each of the five mass extinctions (end-Ordovician, Late Devonian, end-Permian, end-Triassic, and end-Cretaceous). Our hypothesis was that the average biovolume of animals increased after each of the extinctions, with the mean size being greater after than it was before. Our size data is from the Ellis & Messina Catalogue of Ostracoda and the Treatise on Invertebrate Paleontology. We obtained stratigraphic range data The Treatise and Sepkoski (2002). In our analyses, we compared the mean size of the different animal genera before and after each extinction event. We further partitioned size change across mass extinction boundaries into three categories: the surviving genera, the extinct genera, and the newly originating genera that came about after the extinction. According to our analyses, the mean sizes did not change significantly from the genera living during the stages before the extinctions and after the extinctions. From our results, we can assume that there were not enough major increases in the overall volume of the organisms to warrant a definite conclusion that extinctions lead to larger body sizes. Further support for our findings came from the T-tests in our R code. Only the Cretaceous period showed true evidence for size changing because of the extinction; in this case, the mean size decreased. T-tests for the Cretaceous

Modeling Natural Selection

ERIC Educational Resources Information Center

Bogiages, Christopher A.; Lotter, Christine

2011-01-01

In their research, scientists generate, test, and modify scientific models. These models can be shared with others and demonstrate a scientist's understanding of how the natural world works. Similarly, students can generate and modify models to gain a better understanding of the content, process, and nature of science (Kenyon, Schwarz, and Hug…

Natural selection and the evolution of reproductive effort.

PubMed

Hirshfield, M F; Tinkle, D W

1975-06-01

Reproductive effort is defined as that proportion of the total energy budget of an organism that is devoted to reproductive processes. Reproductive effort at a given age within a species will be selected to maximize reproductive value at that age. Reproductive effort is not directly affected by changes in juvenile survivorship, nor necessarily reduced by an increase in adult survivorship. Selection for high levels of reproductive effort should occur when extrinsic adult mortality is high, in environments with constant juvenile survivorship, and in good years for juvenile survivorship in a variable environment, provided that the quality of the year is predictable by adults. Data necessary to measure reproductive effort and to understand how selection results in different levels of effort between individuals and species are discussed. We make several predictions about the effect of increased resource availability on reproductive effort. The empirical bases for testing these predictions are presently inadequate, and we consider data on energy budgets of organisms in nature to be essential for such test. We also conclude that variance in life table parameters must be known in detail to understand the selective bases of levels of reproductive effort.

Cyclone tolerance in new world arecaceae: biogeographic variation and abiotic natural selection.

PubMed

Griffith, M Patrick; Noblick, Larry R; Dowe, John L; Husby, Chad E; Calonje, Michael A

2008-10-01

Consistent abiotic factors can affect directional selection; cyclones are abiotic phenomena with near-discrete geographic limits. The current study investigates selective pressure of cyclones on plants at the species level, testing for possible natural selection. New World Arecaceae (palms) are used as a model system, as plants with monopodial, unbranched arborescent form are most directly affected by the selective pressure of wind load. Living specimens of known provenance grown at a common site were affected by the same cyclone. Data on percentage mortality were compiled and analysed in biogeographic and phylogenetic contexts. Palms of cyclone-prone provenance exhibited a much lower (one order of magnitude) range in cyclone tolerance, and significantly lower (P < 0.001) mean percentage mortality than collections from cyclone-free areas. Palms of cyclone-free provenance had much greater variation in tolerance, and significantly greater mean percentage mortality. A test for serial independence recovered no significant phylogenetic autocorrelation of percentage mortality. Variation in cyclone tolerance in New World Arecaceae correlates with biogeography, and is not confounded with phylogeny. These results suggest natural selection of cyclone tolerance in cyclone-prone areas.

Substitution rate and natural selection in parvovirus B19

PubMed Central

Stamenković, Gorana G.; Ćirković, Valentina S.; Šiljić, Marina M.; Blagojević, Jelena V.; Knežević, Aleksandra M.; Joksić, Ivana D.; Stanojević, Maja P.

2016-01-01

The aim of this study was to estimate substitution rate and imprints of natural selection on parvovirus B19 genotype 1. Studied datasets included 137 near complete coding B19 genomes (positions 665 to 4851) for phylogenetic and substitution rate analysis and 146 and 214 partial genomes for selection analyses in open reading frames ORF1 and ORF2, respectively, collected 1973–2012 and including 9 newly sequenced isolates from Serbia. Phylogenetic clustering assigned majority of studied isolates to G1A. Nucleotide substitution rate for total coding DNA was 1.03 (0.6–1.27) x 10−4 substitutions/site/year, with higher values for analyzed genome partitions. In spite of the highest evolutionary rate, VP2 codons were found to be under purifying selection with rare episodic positive selection, whereas codons under diversifying selection were found in the unique part of VP1, known to contain B19 immune epitopes important in persistent infection. Analyses of overlapping gene regions identified nucleotide positions under opposite selective pressure in different ORFs, suggesting complex evolutionary mechanisms of nucleotide changes in B19 viral genomes. PMID:27775080

From Ends to Causes (and Back Again) by Metaphor: The Paradox of Natural Selection

NASA Astrophysics Data System (ADS)

Blancke, Stefaan; Schellens, Tammy; Soetaert, Ronald; Van Keer, Hilde; Braeckman, Johan

2014-04-01

Natural selection is one of the most famous metaphors in the history of science. Charles Darwin used the metaphor and the underlying analogy to frame his ideas about evolution and its main driving mechanism into a full-fledged theory. Because the metaphor turned out to be such a powerful epistemic tool, Darwin naturally assumed that he could also employ it as an educational tool to inform his contemporaries about his findings. Moreover, by using the metaphor Darwin was able to bring his theory in accordance with both the dominant philosophy of science in his time and the respected tradition of natural theology. However, as he introduced his theory of evolution by natural selection in On the origin of species in 1859, the metaphor also turned out to have a serious downside. Because of its intentional overtones, his contemporaries systematically misunderstood his metaphor not as a natural mechanism causing evolution to occur but as an agent who works towards particular ends. The difference in success between natural selection as an epistemic tool and its failure as an educational tool is labelled as a paradox. We explain the paradox from a cognitive perspective and discuss the implications for teaching evolution.

The paradoxical advantages and disadvantages of natural selection: the case history of Charles Darwin.

PubMed

Lieb, J

2007-01-01

The biology of natural selection is an enduring mystery, as is the nature of Charles Darwin's chronic illness. Of the theories advanced to explain the latter, Oedipal conflicts and Chagas' disease are preeminent. Hypomania, however, propelled Darwin to the pinnacle of scientific achievement and good health, the depression that followed condemning him to intellectual stagnation, lethargy, impaired memory and concentration, and incapacitating gastrointestinal disorders. Examples of natural selection in humans are much sought after when, ironically, one need look no further than Darwin himself.

Unweaving misconceptions: Guided learning, simulations, and misconceptions in learning principles of natural selection

NASA Astrophysics Data System (ADS)

Weeks, Brian E.

College students often come to the study of evolutionary biology with many misconceptions of how the processes of natural selection and speciation occur. How to relinquish these misconceptions with learners is a question that many educators face in introductory biology courses. Constructivism as a theoretical framework has become an accepted and promoted model within the epistemology of science instruction. However, constructivism is not without its skeptics who see some problems of its application in lacking necessary guidance for novice learners. This study within a quantitative, quasi-experimental format tested whether guided online instruction in a video format of common misconceptions in evolutionary biology produced higher performance on a survey of knowledge of natural selection versus more constructivist style learning in the form of student exploration of computer simulations of the evolutionary process. Performances on surveys were also explored for a combination of constructivist and guided techniques to determine if a consolidation of approaches produced higher test scores. Out of the 94 participants 95% displayed at least one misconception of natural selection in the pre-test while the study treatments produced no statistically significant improvements in post-test scores except within the video (guided learning treatment). These overall results demonstrated the stubbornness of misconceptions involving natural selection for adult learners and the difficulty of helping them overcome them. It also bolsters the idea that some misconceptions of natural selection and evolution may be hardwired in a neurological sense and that new, more long-term teaching techniques may be warranted. Such long-term strategies may not be best implemented with constructivist techniques alone, and it is likely that some level of guidance may be necessary for novice adult learners. A more substantial, nuanced approach for undergraduates is needed that consolidates successful

Knowledge, Affection and Basic Attitudes Toward Animals in American Society. Phase III.

ERIC Educational Resources Information Center

Kellert, Stephen R.; Berry, Joyce K.

This paper, third in a series of five reports on results of a national study of American attitudes, knowledge, and behaviors toward wildlife and natural habitats, focuses on the American public's attitudes, perceptions, and understanding of animals. Data were derived from questionnaires administered to 3,107 randomly selected Americans (18 years…

Selection criteria for forested natural areas in New England, USA

Treesearch

William B. Leak; Mariko Yamasaki; Marie-Louise Smith; David T. Funk

1994-01-01

The selection of forested natural areas for research and educational purposes is discussed. Five factors are important: sufficient size; representation of typical communities and sites; documented disturbance histories; acceptable current condition in terms of age, tree size, and successional stage; and administrative feasibility.

Tardigrades living in extreme environments have naturally selected prerequisites useful to space conquer

NASA Astrophysics Data System (ADS)

Guidetti, Roberto; Tiziana, Altiero; Cesari, Michele; Rizzo, Angela Maria; Bertolani, Roberto; Galletta, Giuseppe; Dalessandro, Maurizio; Rebecchi, Lorena

Extreme habitats are highly selective and can host only living organisms possessing specific adaptations to stressors. Among extreme habitats, space environment has particular charac-teristics of radiations, vacuum, microgravity and temperature, which induce rapid changes in living systems. Consequently, the response of multicellular complex organisms, able to colo-nize extreme environments, to space stresses can give very useful information on the ability to withstand a single stress or stress combinations. This knowledge on changes in living systems in space, with their similarity to the ageing processes, offers the opportunity to improve human life both on Earth and in space. Even though experimentation in space has often been carried out using unicellular organisms, multicellular organisms are very relevant in order to develop the appropriate countermeasures to avoid the risks imposed by environmental space in humans. The little attention received by multicellular organisms is probably due, other than to difficul-ties in the manipulation of biological materials in space, to the presence of only few organisms with the potential to tolerate environmental space stresses. Among them, tardigrades are small invertebrates representing an attractive animal model to study adaptive strategies for surviving extreme environments, including space environment. Tardigrades are little known microscopic aquatic animals (250-800 m in body length) distributed in different environments (from the deep sea to high mountains and deserts all over the world), and frequently inhabiting very unstable and unpredictable habitats (e.g. interstices of mosses, lichens, leaf litter, freshwater ponds, cryoconite holes). Their ability to live in the extreme environments is related to a wide variety of their life histories and adaptive strategies. A widespread and crucial strategy is cryptobiosis, a form of quiescence. It includes strategies such as anhydrobiosis and cryobiosis, characterized by

Novel natural food antimicrobials.

PubMed

Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

Genomic Tools and Animal Health.

PubMed

Zanella, Ricardo

2016-09-07

Animals have been selected to improve their productivity in order to increase the profitability to the producer. In this scenario, not much attention was given to health traits. As a consequence of that, selection was made for animals with higher production and a shortened productive life. In addition to that, the intense production system used in livestock has forced animals to be exposed to higher pathogen loads, therefore predisposing them to infections. Infectious diseases are known to be caused by micro-organisms that are able to infect and colonize the host, affecting their physiological functions and causing problems in their production and on animal welfare. Even with the best management practices, diseases are still the most important cause of economic losses in the animal industry. In this review article we have addressed the new tools that could be used to select animals to better cope with diseases and pathogens.

Select Agent and Toxin Regulations: Beyond the Eighth Edition of the Guide for the Care and Use of Laboratory Animals

PubMed Central

Kastenmayer, Robin J; Moore, Rashida M; Bright, Allison L; Torres-Cruz, Rafael; Elkins, William R

2012-01-01

In the interval between the publication of the seventh and eighth editions of the Guide for the Care and Use of Laboratory Animals (Guide), much has changed with regard to the regulation and funding of highly pathogenic biologic agents and toxins (Select Agents). Funding of research involving highly pathogenic agents has increased dramatically during this time, thus increasing the demand for facilities capable of supporting this work. The eighth edition of the Guide briefly mentions Select Agents and provides a limited set of references. Here we provide some background information regarding the relevant laws and regulations, as well as an overview of the programmatic requirements pertaining to the use of Select Agents, with a focus on use in animals. PMID:22776191

Animal Detectives

ERIC Educational Resources Information Center

Mulvey, Bridget; Warnock, Carly

2015-01-01

During a two-week inquiry-based 5E learning cycle unit, children made observations and inferences to guide their explorations of animal traits and habitats (Bybee 2014). The children became "animal detectives" by studying a live-feed webcam and digital images of wolves in their natural habitat, reading books and online sources about…

Lied Animal Shelter Animal campus Renewable Energy Demonstration Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Randy Spitzmesser, AIA

2005-11-22

The Animal Shelter campus plan includes a new adoption center coupled with a dog adoption park, a wellness/veterinary technician education center, a show arena, and an addition to the existing shelter that will accommodate all animal control and sheltering for the Las Vegas Valley. The new facility will provide a sophisticated and innovative presentation of the animals to be adopted in an attempt to improve the public's perception of shelter animals. Additionally, the Regional Animal Campus will be a ''green building'', embodying a design intent on balancing environmental responsiveness, resource efficiency and cultural and community sensitivity. Designing an energy-efficient buildingmore » helps reduce pollution from burning fossil fuels, reduce disturbance of natural habitats for the harvesting of resources and minimizes global warming. The project will be a leader in the use of renewable energy by relying on photovoltaic panels, wind turbines, and solar collectors to produce a portion of the project's energy needs The building will operate more efficiently in comparison to a typical shelter through the use of monitoring and specialized cooling/heating equipment. Windows bringing in natural daylight will reduce the center's demand for electricity.« less

Gis-Based Site Selection for Underground Natural Resources Using Fuzzy Ahp-Owa

NASA Astrophysics Data System (ADS)

Sabzevari, A. R.; Delavar, M. R.

2017-09-01

Fuel consumption has significantly increased due to the growth of the population. A solution to address this problem is the underground storage of natural gas. The first step to reach this goal is to select suitable places for the storage. In this study, site selection for the underground natural gas reservoirs has been performed using a multi-criteria decision-making in a GIS environment. The "Ordered Weighted Average" (OWA) operator is one of the multi-criteria decision-making methods for ranking the criteria and consideration of uncertainty in the interaction among the criteria. In this paper, Fuzzy AHP_OWA (FAHP_OWA) is used to determine optimal sites for the underground natural gas reservoirs. Fuzzy AHP_OWA considers the decision maker's risk taking and risk aversion during the decision-making process. Gas consumption rate, temperature, distance from main transportation network, distance from gas production centers, population density and distance from gas distribution networks are the criteria used in this research. Results show that the northeast and west of Iran and the areas around Tehran (Tehran and Alborz Provinces) have a higher attraction for constructing a natural gas reservoir. The performance of the used method was also evaluated. This evaluation was performed using the location of the existing natural gas reservoirs in the country and the site selection maps for each of the quantifiers. It is verified that the method used in this study is capable of modeling different decision-making strategies used by the decision maker with about 88 percent of agreement between the modeling and test data.

Why Did You Choose This Pet?: Adopters and Pet Selection Preferences in Five Animal Shelters in the United States

PubMed Central

Weiss, Emily; Miller, Katherine; Mohan-Gibbons, Heather; Vela, Carla

2012-01-01

Simple Summary This study examined reasons why adopters chose their pet in an animal shelter, what behaviors were first exhibited by the pet to the adopter, what information was important during their selection process, and the relative importance of seeing the animals’ behavior in various contexts. Abstract Responses from an adopter survey (n = 1,491) determined reasons for pet selection, type of information received by the adopter, and the context in which the animal’s behavior was observed. Appearance of the animal, social behavior with adopter, and personality were the top reasons for adoption across species and age groups. Most adopters stated that information about the animal from a staff member or volunteer was more important than information on cage cards, and health and behavior information was particularly important. Adopters found greater importance in interacting with the animal rather than viewing it in its kennel. The results of this study can be used by shelters to create better adoption matches, prioritize shelter resources and staff training, and potentially increase adoptions. Additionally, some simple training techniques are suggested to facilitate adopter-friendly behaviors from sheltered dogs and cats. PMID:26486914

Effects of the Ordering of Natural Selection and Population Regulation Mechanisms on Wright-Fisher Models

PubMed Central

He, Zhangyi; Beaumont, Mark; Yu, Feng

2017-01-01

We explore the effect of different mechanisms of natural selection on the evolution of populations for one- and two-locus systems. We compare the effect of viability and fecundity selection in the context of the Wright-Fisher model with selection under the assumption of multiplicative fitness. We show that these two modes of natural selection correspond to different orderings of the processes of population regulation and natural selection in the Wright-Fisher model. We find that under the Wright-Fisher model these two different orderings can affect the distribution of trajectories of haplotype frequencies evolving with genetic recombination. However, the difference in the distribution of trajectories is only appreciable when the population is in significant linkage disequilibrium. We find that as linkage disequilibrium decays the trajectories for the two different models rapidly become indistinguishable. We discuss the significance of these findings in terms of biological examples of viability and fecundity selection, and speculate that the effect may be significant when factors such as gene migration maintain a degree of linkage disequilibrium. PMID:28500051

Natural selection drives chemical resistance of Datura stramonium

PubMed Central

Miranda-Pérez, Adán; Castillo, Guillermo; Hernández-Cumplido, Johnattan; Valverde, Pedro L.; Borbolla, María; Cruz, Laura L.; Tapia-López, Rosalinda; Fornoni, Juan; Flores-Ortiz, César M.

2016-01-01

Plant resistance to herbivores involves physical and chemical plant traits that prevent or diminish damage by herbivores, and hence may promote coevolutionary arm-races between interacting species. Although Datura stramonium’s concentration of tropane alkaloids is under selection by leaf beetles, it is not known whether chemical defense reduces seed predation by the specialist weevil, Trichobaris soror, and if it is evolving by natural selection. We measured infestation by T. soror as well as the concentration of the plants’ two main tropane alkaloids in 278 D. stramonium plants belonging to 31 populations in central Mexico. We assessed whether the seed predator exerted preferences on the levels of both alkaloids and whether they affect plant fitness. Results show great variation across populations in the concentration of scopolamine and atropine in both leaves and seeds of plants of D. stramonium, as well as in the intensity of infestation and the proportion of infested fruits by T. soror. The concentration of scopolamine in seeds and leaves are negatively associated across populations. We found that scopolamine concentration increases plant fitness. Our major finding was the detection of a positive relationship between the population average concentrations of scopolamine with the selection differentials of scopolamine. Such spatial variation in the direction and intensity of selection on scopolamine may represent a coevolutionary selective mosaic. Our results support the view that variation in the concentration of scopolamine among-populations of D. stramonium in central Mexico is being driven, in part, by selection exerted by T. soror, pointing an adaptive role of tropane alkaloids in this plant species. PMID:27114866

Using Animation to Convey Natural Hazards and Anthropogenic Change

NASA Astrophysics Data System (ADS)

Kerlow, Isaac

2016-04-01

Moving images are a powerful medium for analyzing, exploring and visually communicating complex concepts, and they are also the premiere medium for contemporary storytelling. Animation is particularly adept for explaining complex concepts and also for creating emotional messages. On a practical level animation can be free from the production constraints and the expense of live action filming. This presentation shows and explains a variety of Earth-inspired animated sequences produced by the Art+Media Research Group at the Earth Observatory of Singapore. These animations have been used in a variety of interdisciplinary projects with multiple roles: sometimes to clearly explain a concept, others to elicit a feeling, or to present an emotion that facilitates learning. The projects reviewed range from scientific documentaries, to narrative shorts and interactive games. http://art-science-media.com/

Using Animation to Convey Natural Hazards and Anthropogenic Change

NASA Astrophysics Data System (ADS)

Kerlow, I.

2016-12-01

Moving images are a powerful medium for analyzing, exploring and visually communicating complex concepts, and they are also the premiere medium for contemporary storytelling. Animation is particularly adept for explaining complex concepts and also for creating emotional messages. On a practical level animation can be free from the production constraints and the expense of live action filming. This presentation shows and explains new Earth-inspired animated sequences produced by the Art+Media Research Group at the Earth Observatory of Singapore. These animations have been used in a variety of interdisciplinary projects with multiple roles: sometimes to clearly explain a concept, others to elicit a feeling, or to present an emotion that facilitates learning. The projects reviewed range from scientific documentaries, to narrative shorts and interactive games. http://art-science-media.com/

A natural outbreak of Aujeszky's disease in farm animals.

PubMed

Salwa, A

2004-01-01

An outbreak of Aujeszky's disease (AD) occurred in a herd of domestic animals that led to the death of seven cattle, three goats, three sheep, two cats and one dog, all of them with CNS signs. The animals were not in direct contact with swine. The ADV was detected in the tissue of affected animals by celi culture methods and PCR. Genome strains of ADV were characterized by restriction endonuclease analysis using BamH I. The results indicated that the strains of virus were identical and belonged to the type genome I of AD. Compared with vaccine and isolated strains obtained from the pig in the same region, considerable differences in DNA patterns were detected. Interestingly, the strains isolated from the dead animals were similar to Buk T-900 reference strains.

How Can We Study the Evolution of Animal Minds?

PubMed Central

Cauchoix, Maxime; Chaine, Alexis S.

2016-01-01

During the last 50 years, comparative cognition and neurosciences have improved our understanding of animal minds while evolutionary ecology has revealed how selection acts on traits through evolutionary time. We describe how cognition can be subject to natural selection like any other biological trait and how this evolutionary approach can be used to understand the evolution of animal cognition. We recount how comparative and fitness methods have been used to understand the evolution of cognition and outline how these approaches could extend our understanding of cognition. The fitness approach, in particular, offers unprecedented opportunities to study the evolutionary mechanisms responsible for variation in cognition within species and could allow us to investigate both proximate (i.e., neural and developmental) and ultimate (i.e., ecological and evolutionary) underpinnings of animal cognition together. We highlight recent studies that have successfully shown that cognitive traits can be under selection, in particular by linking individual variation in cognition to fitness. To bridge the gap between cognitive variation and fitness consequences and to better understand why and how selection can occur on cognition, we end this review by proposing a more integrative approach to study contemporary selection on cognitive traits combining socio-ecological data, minimally invasive neuroscience methods and measurement of ecologically relevant behaviors linked to fitness. Our overall goal in this review is to build a bridge between cognitive neuroscientists and evolutionary biologists, illustrate how their research could be complementary, and encourage evolutionary ecologists to include explicit attention to cognitive processes in their studies of behavior. PMID:27014163

Characterization of the transcriptome, nucleotide sequence polymorphism, and natural selection in the desert adapted mouse Peromyscus eremicus.

PubMed

MacManes, Matthew D; Eisen, Michael B

2014-01-01

As a direct result of intense heat and aridity, deserts are thought to be among the most harsh of environments, particularly for their mammalian inhabitants. Given that osmoregulation can be challenging for these animals, with failure resulting in death, strong selection should be observed on genes related to the maintenance of water and solute balance. One such animal, Peromyscus eremicus, is native to the desert regions of the southwest United States and may live its entire life without oral fluid intake. As a first step toward understanding the genetics that underlie this phenotype, we present a characterization of the P. eremicus transcriptome. We assay four tissues (kidney, liver, brain, testes) from a single individual and supplement this with population level renal transcriptome sequencing from 15 additional animals. We identified a set of transcripts undergoing both purifying and balancing selection based on estimates of Tajima's D. In addition, we used the branch-site test to identify a transcript-Slc2a9, likely related to desert osmoregulation-undergoing enhanced selection in P. eremicus relative to a set of related non-desert rodents.

[Animal experimentation, animal welfare and scientific research].

PubMed

Tal, H

2013-10-01

Hundreds of thousands of laboratory animals are being used every year for scientific experiments held in Israel, mostly mice, rats, rabbits, guinea pigs, and a few sheep, cattle, pigs, cats, dogs, and even a few dozen monkeys. In addition to the animals sacrificed to promote scientific research, millions of animals slain every year for other purposes such as meat and fine leather fashion industries. While opening a front against all is an impossible and perhaps an unjustified task, the state of Israel enacted the Animal Welfare (Animal Experimentation) Law (1994). The law aims to regulate scientific animal experiments and to find the appropriate balance between the need to continue to perform animal experiments for the advancement of research and medicine, and at the same time to avoid unnecessary trials and minimize animal suffering. Among other issues the law deals with the phylogenetic scale according to which experimental animals should be selected, experiments for teaching and practicing, and experiments for the cosmetic industry. This article discusses bioethics considerations in animal experiments as well as the criticism on the scientific validity of such experiments. It further deals with the vitality of animal studies and the moral and legal obligation to prevent suffering from laboratory animals.

Are heritability and selection related to population size in nature? Meta-analysis and conservation implications.

PubMed

Wood, Jacquelyn L A; Yates, Matthew C; Fraser, Dylan J

2016-06-01

It is widely thought that small populations should have less additive genetic variance and respond less efficiently to natural selection than large populations. Across taxa, we meta-analytically quantified the relationship between adult census population size (N) and additive genetic variance (proxy: h (2)) and found no reduction in h (2) with decreasing N; surveyed populations ranged from four to one million individuals (1735 h (2) estimates, 146 populations, 83 species). In terms of adaptation, ecological conditions may systematically differ between populations of varying N; the magnitude of selection these populations experience may therefore also differ. We thus also meta-analytically tested whether selection changes with N and found little evidence for systematic differences in the strength, direction or form of selection with N across different trait types and taxa (7344 selection estimates, 172 populations, 80 species). Collectively, our results (i) indirectly suggest that genetic drift neither overwhelms selection more in small than in large natural populations, nor weakens adaptive potential/h (2) in small populations, and (ii) imply that natural populations of varying sizes experience a variety of environmental conditions, without consistently differing habitat quality at small N. However, we caution that the data are currently insufficient to determine whether some small populations may retain adaptive potential definitively. Further study is required into (i) selection and genetic variation in completely isolated populations of known N, under-represented taxonomic groups, and nongeneralist species, (ii) adaptive potential using multidimensional approaches and (iii) the nature of selective pressures for specific traits.

Determination of selected neurotoxic insecticides in small amounts of animal tissue utilizing a newly constructed mini-extractor.

PubMed

Seifertová, Marta; Čechová, Eliška; Llansola, Marta; Felipo, Vicente; Vykoukalová, Martina; Kočan, Anton

2017-10-01

We developed a simple analytical method for the simultaneous determination of representatives of various groups of neurotoxic insecticides (carbaryl, chlorpyrifos, cypermethrin, and α-endosulfan and β-endosulfan and their metabolite endosulfan sulfate) in limited amounts of animal tissues containing different amounts of lipids. Selected tissues (rodent fat, liver, and brain) were extracted in a special in-house-designed mini-extractor constructed on the basis of the Soxhlet and Twisselmann extractors. A dried tissue sample placed in a small cartridge was extracted, while the nascent extract was simultaneously filtered through a layer of sodium sulfate. The extraction was followed by combined clean-up, including gel permeation chromatography (in case of high lipid content), ultrasonication, and solid-phase extraction chromatography using C 18 on silica and aluminum oxide. Gas chromatography coupled with high-resolution mass spectrometry was used for analyte separation, detection, and quantification. Average recoveries for individual insecticides ranged from 82 to 111%. Expanded measurement uncertainties were generally lower than 35%. The developed method was successfully applied to rat tissue samples obtained from an animal model dealing with insecticide exposure during brain development. This method may also be applied to the analytical treatment of small amounts of various types of animal and human tissue samples. A significant advantage achieved using this method is high sample throughput due to the simultaneous treatment of many samples. Graphical abstract Optimized workflow for the determination of selected insecticides in small amounts of animal tissue including newly developed mini-extractor.

Natural selection of memory-one strategies for the iterated prisoner's dilemma.

PubMed

Kraines, D P; Kraines, V Y

2000-04-21

In the iterated Prisoner's Dilemma, mutually cooperative behavior can become established through Darwinian natural selection. In simulated interactions of stochastic memory-one strategies for the Iterated Prisoner's Dilemma, Nowak and Sigmund discovered that cooperative agents using a Pavlov (Win-Stay Lose-Switch) type strategy eventually dominate a random population. This emergence follows more directly from a deterministic dynamical system based on differential reproductive success or natural selection. When restricted to an environment of memory-one agents interacting in iterated Prisoner's Dilemma games with a 1% noise level, the Pavlov agent is the only cooperative strategy and one of very few others that cannot be invaded by a similar strategy. Pavlov agents are trusting but no suckers. They will exploit weakness but repent if punished for cheating. Copyright 2000 Academic Press.

Strong and consistent natural selection associated with armour reduction in sticklebacks.

PubMed

LE Rouzic, Arnaud; Østbye, Kjartan; Klepaker, Tom O; Hansen, Thomas F; Bernatchez, Louis; Schluter, Dolph; Vøllestad, L Asbjørn

2011-06-01

Measuring the strength of natural selection is tremendously important in evolutionary biology, but remains a challenging task. In this work, we analyse the characteristics of selection for a morphological change (lateral-plate reduction) in the threespine stickleback Gasterosteus aculeatus. Adaptation to freshwater, leading with the reduction or loss of the bony lateral armour, has occurred in parallel on numerous occasions in this species. Completely-plated and low-plated sticklebacks were introduced into a pond, and the phenotypic changes were tracked for 20 years. Fish from the last generation were genotyped for the Ectodysplasin-A (Eda) locus, the major gene involved in armour development. We found a strong fitness advantage for the freshwater-type fish (on average, 20% fitness advantage for the freshwater morph, and 92% for the freshwater genotype). The trend is best explained by assuming that this fitness advantage is maximum at the beginning of the invasion and decreases with time. Such fitness differences provide a quantifiable example of rapid selection-driven phenotypic evolution associated with environmental change in a natural population. © 2011 Blackwell Publishing Ltd.

Animal Communication: What Do Animals Say?

ERIC Educational Resources Information Center

Morton, Eugene S.

1983-01-01

Discusses the nature of animal communication, including possible relationships between the physical structure of vocalizations and their functions in communicating. Provides tables of mammalian and avian sounds (by species/family) used in hostile and friendly appeasing contexts. (JN)

Genetic polymorphism and natural selection of Duffy binding protein of Plasmodium vivax Myanmar isolates

PubMed Central

2012-01-01

Background Plasmodium vivax Duffy binding protein (PvDBP) plays an essential role in erythrocyte invasion and a potential asexual blood stage vaccine candidate antigen against P. vivax. The polymorphic nature of PvDBP, particularly amino terminal cysteine-rich region (PvDBPII), represents a major impediment to the successful design of a protective vaccine against vivax malaria. In this study, the genetic polymorphism and natural selection at PvDBPII among Myanmar P. vivax isolates were analysed. Methods Fifty-four P. vivax infected blood samples collected from patients in Myanmar were used. The region flanking PvDBPII was amplified by PCR, cloned into Escherichia coli, and sequenced. The polymorphic characters and natural selection of the region were analysed using the DnaSP and MEGA4 programs. Results Thirty-two point mutations (28 non-synonymous and four synonymous mutations) were identified in PvDBPII among the Myanmar P. vivax isolates. Sequence analyses revealed that 12 different PvDBPII haplotypes were identified in Myanmar P. vivax isolates and that the region has evolved under positive natural selection. High selective pressure preferentially acted on regions identified as B- and T-cell epitopes of PvDBPII. Recombination may also be played a role in the resulting genetic diversity of PvDBPII. Conclusions PvDBPII of Myanmar P. vivax isolates displays a high level of genetic polymorphism and is under selective pressure. Myanmar P. vivax isolates share distinct types of PvDBPII alleles that are different from those of other geographical areas. These results will be useful for understanding the nature of the P. vivax population in Myanmar and for development of PvDBPII-based vaccine. PMID:22380592

A Collective Case Study of Secondary Students' Model-Based Inquiry on Natural Selection through Programming in an Agent-Based Modeling Environment

NASA Astrophysics Data System (ADS)

Xiang, Lin

This is a collective case study seeking to develop detailed descriptions of how programming an agent-based simulation influences a group of 8 th grade students' model-based inquiry (MBI) by examining students' agent-based programmable modeling (ABPM) processes and the learning outcomes. The context of the present study was a biology unit on natural selection implemented in a charter school of a major California city during spring semester of 2009. Eight 8th grade students, two boys and six girls, participated in this study. All of them were low socioeconomic status (SES). English was a second language for all of them, but they had been identified as fluent English speakers at least a year before the study. None of them had learned either natural selection or programming before the study. The study spanned over 7 weeks and was comprised of two study phases. In phase one the subject students learned natural selection in science classroom and how to do programming in NetLogo, an ABPM tool, in a computer lab; in phase two, the subject students were asked to program a simulation of adaptation based on the natural selection model in NetLogo. Both qualitative and quantitative data were collected in this study. The data resources included (1) pre and post test questionnaire, (2) student in-class worksheet, (3) programming planning sheet, (4) code-conception matching sheet, (5) student NetLogo projects, (6) videotaped programming processes, (7) final interview, and (8) investigator's field notes. Both qualitative and quantitative approaches were applied to analyze the gathered data. The findings suggested that students made progress on understanding adaptation phenomena and natural selection at the end of ABPM-supported MBI learning but the progress was limited. These students still held some misconceptions in their conceptual models, such as the idea that animals need to "learn" to adapt into the environment. Besides, their models of natural selection appeared to be

Intraspecific eye color variability in birds and mammals: a recent evolutionary event exclusive to humans and domestic animals.

PubMed

Negro, Juan J; Carmen Blázquez, M; Galván, Ismael

2017-01-01

Human populations and breeds of domestic animals are composed of individuals with a multiplicity of eye (= iris) colorations. Some wild birds and mammals may have intraspecific eye color variability, but this variation seems to be due to the developmental stage of the individual, its breeding status, and/or sexual dimorphism. In other words, eye colour tends to be a species-specific trait in wild animals, and the exceptions are species in which individuals of the same age group or gender all develop the same eye colour. Domestic animals, by definition, include bird and mammal species artificially selected by humans in the last few thousand years. Humans themselves may have acquired a diverse palette of eye colors, likewise in recent evolutionary time, in the Mesolithic or in the Upper Paleolithic. We posit two previously unrecognized hypotheses regarding eye color variation: 1) eye coloration in wild animals of every species tends to be a fixed trait. 2) Humans and domestic animal populations, on the contrary, have eyes of multiple colors. Sexual selection has been invoked for eye color variation in humans, but this selection mode does not easily apply in domestic animals, where matings are controlled by the human breeder. Eye coloration is polygenic in humans. We wish to investigate the genetics of eye color in other animals, as well as the ecological correlates. Investigating the origin and function of eye colors will shed light on the reason why some species may have either light-colored irises (e.g., white, yellow or light blue) or dark ones (dark red, brown or black). The causes behind the vast array of eye colors across taxa have never been thoroughly investigated, but it may well be that all Darwinian selection processes are at work: sexual selection in humans, artificial selection for domestic animals, and natural selection (mainly) for wild animals.

Genetic signatures of natural selection in a model invasive ascidian

NASA Astrophysics Data System (ADS)

Lin, Yaping; Chen, Yiyong; Yi, Changho; Fong, Jonathan J.; Kim, Won; Rius, Marc; Zhan, Aibin

2017-03-01

Invasive species represent promising models to study species’ responses to rapidly changing environments. Although local adaptation frequently occurs during contemporary range expansion, the associated genetic signatures at both population and genomic levels remain largely unknown. Here, we use genome-wide gene-associated microsatellites to investigate genetic signatures of natural selection in a model invasive ascidian, Ciona robusta. Population genetic analyses of 150 individuals sampled in Korea, New Zealand, South Africa and Spain showed significant genetic differentiation among populations. Based on outlier tests, we found high incidence of signatures of directional selection at 19 loci. Hitchhiking mapping analyses identified 12 directional selective sweep regions, and all selective sweep windows on chromosomes were narrow (~8.9 kb). Further analyses indentified 132 candidate genes under selection. When we compared our genetic data and six crucial environmental variables, 16 putatively selected loci showed significant correlation with these environmental variables. This suggests that the local environmental conditions have left significant signatures of selection at both population and genomic levels. Finally, we identified “plastic” genomic regions and genes that are promising regions to investigate evolutionary responses to rapid environmental change in C. robusta.

Genetic signatures of natural selection in a model invasive ascidian

PubMed Central

Lin, Yaping; Chen, Yiyong; Yi, Changho; Fong, Jonathan J.; Kim, Won; Rius, Marc; Zhan, Aibin

2017-01-01

Invasive species represent promising models to study species’ responses to rapidly changing environments. Although local adaptation frequently occurs during contemporary range expansion, the associated genetic signatures at both population and genomic levels remain largely unknown. Here, we use genome-wide gene-associated microsatellites to investigate genetic signatures of natural selection in a model invasive ascidian, Ciona robusta. Population genetic analyses of 150 individuals sampled in Korea, New Zealand, South Africa and Spain showed significant genetic differentiation among populations. Based on outlier tests, we found high incidence of signatures of directional selection at 19 loci. Hitchhiking mapping analyses identified 12 directional selective sweep regions, and all selective sweep windows on chromosomes were narrow (~8.9 kb). Further analyses indentified 132 candidate genes under selection. When we compared our genetic data and six crucial environmental variables, 16 putatively selected loci showed significant correlation with these environmental variables. This suggests that the local environmental conditions have left significant signatures of selection at both population and genomic levels. Finally, we identified “plastic” genomic regions and genes that are promising regions to investigate evolutionary responses to rapid environmental change in C. robusta. PMID:28266616

Animal Toxins as Therapeutic Tools to Treat Neurodegenerative Diseases

PubMed Central

de Souza, Jessica M.; Goncalves, Bruno D. C.; Gomez, Marcus V.; Vieira, Luciene B.; Ribeiro, Fabiola M.

2018-01-01

Neurodegenerative diseases affect millions of individuals worldwide. So far, no disease-modifying drug is available to treat patients, making the search for effective drugs an urgent need. Neurodegeneration is triggered by the activation of several cellular processes, including oxidative stress, mitochondrial impairment, neuroinflammation, aging, aggregate formation, glutamatergic excitotoxicity, and apoptosis. Therefore, many research groups aim to identify drugs that may inhibit one or more of these events leading to neuronal cell death. Venoms are fruitful natural sources of new molecules, which have been relentlessly enhanced by evolution through natural selection. Several studies indicate that venom components can exhibit selectivity and affinity for a wide variety of targets in mammalian systems. For instance, an expressive number of natural peptides identified in venoms from animals, such as snakes, scorpions, bees, and spiders, were shown to lessen inflammation, regulate glutamate release, modify neurotransmitter levels, block ion channel activation, decrease the number of protein aggregates, and increase the levels of neuroprotective factors. Thus, these venom components hold potential as therapeutic tools to slow or even halt neurodegeneration. However, there are many technological issues to overcome, as venom peptides are hard to obtain and characterize and the amount obtained from natural sources is insufficient to perform all the necessary experiments and tests. Fortunately, technological improvements regarding heterologous protein expression, as well as peptide chemical synthesis will help to provide enough quantities and allow chemical and pharmacological enhancements of these natural occurring compounds. Thus, the main focus of this review is to highlight the most promising studies evaluating animal toxins as therapeutic tools to treat a wide variety of neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, brain

Animation control of surface motion capture.

PubMed

Tejera, Margara; Casas, Dan; Hilton, Adrian

2013-12-01

Surface motion capture (SurfCap) of actor performance from multiple view video provides reconstruction of the natural nonrigid deformation of skin and clothing. This paper introduces techniques for interactive animation control of SurfCap sequences which allow the flexibility in editing and interactive manipulation associated with existing tools for animation from skeletal motion capture (MoCap). Laplacian mesh editing is extended using a basis model learned from SurfCap sequences to constrain the surface shape to reproduce natural deformation. Three novel approaches for animation control of SurfCap sequences, which exploit the constrained Laplacian mesh editing, are introduced: 1) space–time editing for interactive sequence manipulation; 2) skeleton-driven animation to achieve natural nonrigid surface deformation; and 3) hybrid combination of skeletal MoCap driven and SurfCap sequence to extend the range of movement. These approaches are combined with high-level parametric control of SurfCap sequences in a hybrid surface and skeleton-driven animation control framework to achieve natural surface deformation with an extended range of movement by exploiting existing MoCap archives. Evaluation of each approach and the integrated animation framework are presented on real SurfCap sequences for actors performing multiple motions with a variety of clothing styles. Results demonstrate that these techniques enable flexible control for interactive animation with the natural nonrigid surface dynamics of the captured performance and provide a powerful tool to extend current SurfCap databases by incorporating new motions from MoCap sequences.

Images of Animals: Interpreting Three-Dimensional, Life-Sized 'Representations' of Animals--Zoo, Museum and Robotic Animals.

ERIC Educational Resources Information Center

Tunnicliffe, Sue Dale

A visit to the natural history museum is part of many pupils' educational program. One way of investigating what children learn about animals is to examine the mental models they reveal through their talk when they come face to face with animal representations. In this study, representations were provided by: (1) robotic models in a museum; (2)…

No evidence for natural selection on endogenous borna-like nucleoprotein elements after the divergence of Old World and New World monkeys.

PubMed

Kobayashi, Yuki; Horie, Masayuki; Tomonaga, Keizo; Suzuki, Yoshiyuki

2011-01-01

Endogenous Borna-like nucleoprotein (EBLNs) elements were recently discovered as non-retroviral RNA virus elements derived from bornavirus in the genomes of various animals. Most of EBLNs appeared to be defective, but some of primate EBLN-1 to -4, which appeared to be originated from four independent integrations of bornavirus nucleoprotein (N) gene, have retained an open reading frame (ORF) for more than 40 million years. It was therefore possible that primate EBLNs have encoded functional proteins during evolution. To examine this possibility, natural selection operating on all ORFs of primate EBLN-1 to -4 was examined by comparing the rates of synonymous and nonsynonymous substitutions. The expected number of premature termination codons in EBLN-1 generated after the divergence of Old World and New World monkeys under the selective neutrality was also examined by the Monte Carlo simulation. As a result, natural selection was not identified for the entire region as well as parts of ORFs in the pairwise analysis of primate EBLN-1 to -4 and for any branch of the phylogenetic trees for EBLN-1 to -4 after the divergence of Old World and New World monkeys. Computer simulation also indicated that the absence of premature termination codon in the present-day EBLN-1 does not necessarily support the maintenance of function after the divergence of Old World and New World monkeys. These results suggest that EBLNs have not generally encoded functional proteins after the divergence of Old World and New World monkeys.

Notice of release of Amethyst Germplasm hoaty tansyaster: Selected class of natural germplasm

Treesearch

Derek J. Tilley

2015-01-01

The US Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), Aberdeen Plant Materials Center, Aberdeen, Idaho, announces the release of Amethyst Germplasm hoary tansyaster (Machaeronthero canescens (Pursh) A. Gray [Asteraceae]}, a selected class natural track germplasm identified by NRCS accession number 9076670 for conservation plantings in...

A Conservation Ethic and the Collecting of Animals by Institutions of Natural Heritage in the Twenty-First Century: Case Study of the Australian Museum

PubMed Central

Ikin, Timothy

2011-01-01

Simple Summary It is a core task of collecting institutions like museums to take examples of animals and preserve them as specimens in collections. In the twenty-first century, museums are equally the places where research is conducted and education is promoted in the service of conservation of animals in an era of the decline of biodiversity. In this paper, the balance of co-operation between collecting of animals by museums and the promotion and scientific pursuit of conservation of fauna in those museums is considered. As a “challenge” to museum science, it is considered in the context of Australia's oldest museum, and its policy and practice in the current century. Abstract Collecting of animals from their habitats for preservation by museums and related bodies is a core operation of such institutions. Conservation of biodiversity in the current era is a priority in the scientific agendas of museums of natural heritage in Australia and the world. Intuitively, to take animals from the wild, while engaged in scientific or other practices that are supposed to promote their ongoing survival, may appear be incompatible. The Australian Museum presents an interesting ground to consider zoological collecting by museums in the twenty-first century. Anderson and Reeves in 1994 argued that a milieu existed that undervalued native species, and that the role of natural history museums, up to as late as the mid-twentieth century, was only to make a record the faunal diversity of Australia, which would inevitably be extinct. Despite the latter, conservation of Australia's faunal diversity is a key aspect of research programmes in Australia's institutions of natural heritage in the current era. This paper analyses collecting of animals, a core task for institutions of natural heritage, and how this interacts with a professed “conservation ethic” in a twenty-first century Australian setting. PMID:26486222

Natural and cross-inducible anti-SIV antibodies in Mauritian cynomolgus macaques

PubMed Central

Li, Hongzhao; Nykoluk, Mikaela; Li, Lin; Liu, Lewis R.; Omange, Robert W.; Soule, Geoff; Schroeder, Lukas T.; Toledo, Nikki; Kashem, Mohammad Abul; Correia-Pinto, Jorge F.; Liang, Binhua; Schultz-Darken, Nancy; Alonso, Maria J.; Whitney, James B.; Plummer, Francis A.

2017-01-01

Cynomolgus macaques are an increasingly important nonhuman primate model for HIV vaccine research. SIV-free animals without pre-existing anti-SIV immune responses are generally needed to evaluate the effect of vaccine-induced immune responses against the vaccine epitopes. Here, in order to select such animals for vaccine studies, we screened 108 naïve female Mauritian cynomolgus macaques for natural (baseline) antibodies to SIV antigens using a Bio-Plex multiplex system. The antigens included twelve 20mer peptides overlapping the twelve SIV protease cleavage sites (-10/+10), respectively (PCS peptides), and three non-PCS Gag or Env peptides. Natural antibodies to SIV antigens were detected in subsets of monkeys. The antibody reactivity to SIV was further confirmed by Western blot using purified recombinant SIV Gag and Env proteins. As expected, the immunization of monkeys with PCS antigens elicited anti-PCS antibodies. However, unexpectedly, antibodies to non-PCS peptides were also induced, as shown by both Bio-Plex and Western blot analyses, while the non-PCS peptides do not share sequence homology with PCS peptides. The presence of natural and vaccine cross-inducible SIV antibodies in Mauritian cynomolgus macaques should be considered in animal selection, experimental design and result interpretation, for their best use in HIV vaccine research. PMID:28982126

Animals Alive! An Ecological Guide to Animal Activities. Revised Edition.

ERIC Educational Resources Information Center

Holley, Dennis

This guide is designed to help teachers develop an inquiry-oriented program for studying the animal kingdom in which live animals are collected locally, studied, observed, and then released completely unharmed back into their natural habitats. This book addresses such concerns of life science teachers as the environmental soundness of methods and…

Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection

PubMed Central

Glorieux, Cédric; Cuguen, Joel; Roux, Fabrice

2012-01-01

Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously. PMID:22403624

Phenotypic selection on leaf water use efficiency and related ecophysiological traits for natural populations of desert sunflowers.

PubMed

Donovan, Lisa A; Dudley, Susan A; Rosenthal, David M; Ludwig, Fulco

2007-05-01

Plant water-use efficiency (WUE) is expected to affect plant fitness and thus be under natural selection in arid habitats. Although many natural population studies have assessed plant WUE, only a few related WUE to fitness. The further determination of whether selection on WUE is direct or indirect through functionally related traits has yielded no consistent results. For natural populations of two desert annual sunflowers, Helianthus anomalus and H. deserticola, we used phenotypic selection analysis with vegetative biomass as the proxy for fitness to test (1) whether there was direct and indirect selection on WUE (carbon isotope ratio) and related traits (leaf N, area, succulence) and (2) whether direct selection was consistent with hypothesized drought/dehydration escape and avoidance strategies. There was direct selection for lower WUE in mesic and dry H. anomalus populations, consistent with dehydration escape, even though it is the longer lived of the two species. For mesic H. anomalus, direct selection favored lower WUE and higher N, suggesting that plants may be "wasting water" to increase N delivery via the transpiration stream. For the shorter lived H. deserticola in the direr habitat, there was indirect selection for lower WUE, inconsistent with drought escape. There was also direct selection for higher leaf N, succulence and leaf size. There was no direct selection for higher WUE consistent with dehydration avoidance in either species. Thus, in these natural populations of two desert dune species higher fitness was associated with some combination direct and indirect selection for lower WUE, higher leaf N and larger leaf size. Our understanding of the adaptive value of plant ecophysiological traits will benefit from further consideration of related traits such as leaf nitrogen and more tests in natural populations.

Exploration of the Hypothalamic-Pituitary-Adrenal Axis to Improve Animal Welfare by Means of Genetic Selection: Lessons from the South African Merino.

PubMed

Hough, Denise; Swart, Pieter; Cloete, Schalk

2013-05-17

It is a difficult task to improve animal production by means of genetic selection, if the environment does not allow full expression of the animal's genetic potential. This concept may well be the future for animal welfare, because it highlights the need to incorporate traits related to production and robustness, simultaneously, to reach sustainable breeding goals. This review explores the identification of potential genetic markers for robustness within the hypothalamic-pituitary-adrenal axis (HPAA), since this axis plays a vital role in the stress response. If genetic selection for superior HPAA responses to stress is possible, then it ought to be possible to breed robust and easily managed genotypes that might be able to adapt to a wide range of environmental conditions whilst expressing a high production potential. This approach is explored in this review by means of lessons learnt from research on Merino sheep, which were divergently selected for their multiple rearing ability. These two selection lines have shown marked differences in reproduction, production and welfare, which makes this breeding programme ideal to investigate potential genetic markers of robustness. The HPAA function is explored in detail to elucidate where such genetic markers are likely to be found.

Interaction intensity and pollinator-mediated selection.

PubMed

Trunschke, Judith; Sletvold, Nina; Ågren, Jon

2017-05-01

In animal-pollinated plants, the opportunity for selection and the strength of pollinator-mediated selection are expected to increase with the degree of pollen limitation. However, whether differences in pollen limitation can explain variation in pollinator-mediated and net selection among animal-pollinated species is poorly understood. In the present study, we quantified pollen limitation, variance in relative fitness and pollinator-mediated selection on five traits important for pollinator attraction (flowering start, plant height, flower number, flower size) and pollination efficiency (spur length) in natural populations of 12 orchid species. Pollinator-mediated selection was quantified by subtracting estimates of selection gradients for plants receiving supplemental hand-pollination from estimates obtained for open-pollinated control plants. Mean pollen limitation ranged from zero to 0.96. Opportunity for selection, pollinator-mediated selection and net selection were all positively related to pollen limitation, whereas nonpollinator-mediated selection was not. Opportunity for selection varied five-fold, strength of pollinator-mediated selection varied three-fold and net selection varied 1.5-fold among species. Supplemental hand-pollination reduced both opportunity for selection and selection on floral traits. The results show that the intensity of biotic interactions is an important determinant of the selection regime, and indicate that the potential for pollinator-mediated selection and divergence in floral traits is particularly high in species that are strongly pollen-limited. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Animal Watching: Outdoors and In.

ERIC Educational Resources Information Center

McLure, John W.

2001-01-01

Describes using domesticated, wild, or feral animals to teach students about nature and animal behavior. Connections can be made with psychology, economics, genetics, history, art, and other disciplines. The study of animal behavior provides opportunities for harmless student experimentation. (SAH)

Constraint, natural selection, and the evolution of human body form

PubMed Central

Savell, Kristen R. R.; Auerbach, Benjamin M.; Roseman, Charles C.

2016-01-01

Variation in body form among human groups is structured by a blend of natural selection driven by local climatic conditions and random genetic drift. However, attempts to test ecogeographic hypotheses have not distinguished between adaptive traits (i.e., those that evolved as a result of selection) and those that evolved as a correlated response to selection on other traits (i.e., nonadaptive traits), complicating our understanding of the relationship between climate and morphological distinctions among populations. Here, we use evolutionary quantitative methods to test if traits previously identified as supporting ecogeographic hypotheses were actually adaptive by estimating the force of selection on individual traits needed to drive among-group differentiation. Our results show that not all associations between trait means and latitude were caused by selection acting directly on each individual trait. Although radial and tibial length and biiliac and femoral head breadth show signs of responses to directional selection matching ecogeographic hypotheses, the femur was subject to little or no directional selection despite having shorter values by latitude. Additionally, in contradiction to ecogeographic hypotheses, the humerus was under directional selection for longer values by latitude. Responses to directional selection in the tibia and radius induced a nonadaptive correlated response in the humerus that overwhelmed its own trait-specific response to selection. This result emphasizes that mean differences between groups are not good indicators of which traits are adaptations in the absence of information about covariation among characteristics. PMID:27482101

Constraint, natural selection, and the evolution of human body form.

PubMed

Savell, Kristen R R; Auerbach, Benjamin M; Roseman, Charles C

2016-08-23

Variation in body form among human groups is structured by a blend of natural selection driven by local climatic conditions and random genetic drift. However, attempts to test ecogeographic hypotheses have not distinguished between adaptive traits (i.e., those that evolved as a result of selection) and those that evolved as a correlated response to selection on other traits (i.e., nonadaptive traits), complicating our understanding of the relationship between climate and morphological distinctions among populations. Here, we use evolutionary quantitative methods to test if traits previously identified as supporting ecogeographic hypotheses were actually adaptive by estimating the force of selection on individual traits needed to drive among-group differentiation. Our results show that not all associations between trait means and latitude were caused by selection acting directly on each individual trait. Although radial and tibial length and biiliac and femoral head breadth show signs of responses to directional selection matching ecogeographic hypotheses, the femur was subject to little or no directional selection despite having shorter values by latitude. Additionally, in contradiction to ecogeographic hypotheses, the humerus was under directional selection for longer values by latitude. Responses to directional selection in the tibia and radius induced a nonadaptive correlated response in the humerus that overwhelmed its own trait-specific response to selection. This result emphasizes that mean differences between groups are not good indicators of which traits are adaptations in the absence of information about covariation among characteristics.

Carotenoids in Marine Animals

PubMed Central

Maoka, Takashi

2011-01-01

Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade. PMID:21566799

Companion Animals in Natural Disasters: A Scoping Review of Scholarly Sources.

PubMed

Travers, Cheryl; Degeling, Chris; Rock, Melanie

2017-01-01

During a disaster, people may make evacuation decisions based on their companion animal's welfare, therefore exposing themselves, their companion animals, and emergency responders to increased risk for injury or death. The loss and suffering of companion animals in disasters causes deep distress, diminishing people's capacity to rebuild their lives. This scoping review presents scholarly research studies and reviews relating to people and their companion animals in the context of disasters, with an aim of informing researchers, policymakers, and practitioners and providing direction for future research. Using the Arksey and O'Malley framework, articles in scholarly journals from 2004 to 2014 are discussed. Analysis included 38 articles: 20 research studies, 12 reviews, and 6 editorials. Findings revealed 2 central themes: companion animals as a risk factor to human health and safety and companion animals being "at risk" themselves. An emerging theme was "responsibility": Who is responsible for companion animals in disasters and how? Understanding the implications of human-nonhuman animal relationships for disaster response and having a broader public consensus on what is owed to animals at times of emergency are important to community preparedness and resilience.

Rational selection of structurally diverse natural product scaffolds with favorable ADME properties for drug discovery.

PubMed

Samiulla, D S; Vaidyanathan, V V; Arun, P C; Balan, G; Blaze, M; Bondre, S; Chandrasekhar, G; Gadakh, A; Kumar, R; Kharvi, G; Kim, H O; Kumar, S; Malikayil, J A; Moger, M; Mone, M K; Nagarjuna, P; Ogbu, C; Pendhalkar, D; Rao, A V S Raja; Rao, G Venkateshwar; Sarma, V K; Shaik, S; Sharma, G V R; Singh, S; Sreedhar, C; Sonawane, R; Timmanna, U; Hardy, L W

2005-01-01

Natural product analogs are significant sources for therapeutic agents. To capitalize efficiently on the effective features of naturally occurring substances, a natural product-based library production platform has been devised at Aurigene for drug lead discovery. This approach combines the attractive biological and physicochemical properties of natural product scaffolds, provided by eons of natural selection, with the chemical diversity available from parallel synthetic methods. Virtual property analysis, using computational methods described here, guides the selection of a set of natural product scaffolds that are both structurally diverse and likely to have favorable pharmacokinetic properties. The experimental characterization of several in vitro ADME properties of twenty of these scaffolds, and of a small set of designed congeners based upon one scaffold, is also described. These data confirm that most of the scaffolds and the designed library members have properties favorable to their utilization for creating libraries of lead-like molecules.

Microfilaricidal efficacy of a single administration of Advocate(®) (Bayer Animal Health) in dogs naturally infected with Dirofilaria immitis or Dirofilaria repens.

PubMed

Frangipane di Regalbono, Antonio; Di Cesare, Angela; Traversa, Donato; Simonato, Giulia; Poser, Helen; Danesi, Patrizia; Furnari, Carmelo; Russi, Ilaria; Raele, Donato Antonio; Crisi, Paolo; Pampurini, Fabrizio; Pietrobelli, Mario

2016-08-15

The present study evaluated the microfilaricidal efficacy of a single application of the spot-on containing imidacloprid 10%/moxidectin 2.5% (Advocate(®), Bayer Animal Health) in dogs naturally infected either by Dirofilaria immitis or Dirofilaria repens. Dogs living in north-eastern and central-southern Italy, endemic for D. immitis and D. repens respectively, were randomly screened. Sixteen animals, eight infected with D. immitis and eight with D. repens, and fulfilling inclusion criteria were enrolled. Dogs infected with D. immitis received an adulticide treatment prior to the study and Advocate(®) 3 weeks after. The animals were divided in blocks of two (1:1, T1:T2) animals each, where Day 0 (D0) had an interval of 15days to compare T2 vs. T1 dogs during the first fortnight of examination (i.e. T2 dogs acted as control animals at each examination). At baseline (Days -15 and 0 for T2 and T1 dogs, respectively) the animals had a range of microfilaraemia of 180-99.700mff/ml (D. immitis) and 60-750 mff/ml (D. repens). All animals received a topical administration of Advocate(®) at D0 and were examined for microfilariae with microscopic and molecular tests at D15, D30, D60 and D90. All animals scored negative for mff at the first control post-treatment and throughout the study, with the exception of two D. immitis- infected animals that had a 2 mff/ml count at D15, and then become negative from Day 30 onwards. No adverse events were observed. The present study demonstrates the safety and the high microfilaricidal efficacy (99.97% and 100% for D. immitis and D. repens, respectively) of a single dose of moxidectin contained in Advocate(®) in naturally infected dogs. Copyright © 2016 Elsevier B.V. All rights reserved.

Naturally selecting solutions: the use of genetic algorithms in bioinformatics.

PubMed

Manning, Timmy; Sleator, Roy D; Walsh, Paul

2013-01-01

For decades, computer scientists have looked to nature for biologically inspired solutions to computational problems; ranging from robotic control to scheduling optimization. Paradoxically, as we move deeper into the post-genomics era, the reverse is occurring, as biologists and bioinformaticians look to computational techniques, to solve a variety of biological problems. One of the most common biologically inspired techniques are genetic algorithms (GAs), which take the Darwinian concept of natural selection as the driving force behind systems for solving real world problems, including those in the bioinformatics domain. Herein, we provide an overview of genetic algorithms and survey some of the most recent applications of this approach to bioinformatics based problems.

Frugivorous bats maintain functional habitat connectivity in agricultural landscapes but rely strongly on natural forest fragments.

PubMed

Ripperger, Simon P; Kalko, Elisabeth K V; Rodríguez-Herrera, Bernal; Mayer, Frieder; Tschapka, Marco

2015-01-01

Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae), a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radio-tracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest. However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.

Natural selection and sex differences in morbidity and mortality in early life.

PubMed

Wells, J C

2000-01-07

Both morbidity and mortality are consistently reported to be higher in males than in females in early life, but no explanation for these findings has been offered. This paper argues that the sex difference in early vulnerability can be attributed to the natural selection of optimal maternal strategies for maximizing lifetime reproductive success, as modelled previously by Trivers and Willard. These authors theorized that males and females offer different returns on parental investment depending on the state of the environment. Natural selection has therefore favoured maternal ability to manipulate offspring sex in response to environmental conditions in early life, as shown in variation in the sex ratio at birth. This argument can be extended to the whole period of parental investment until weaning. Male vulnerability in response to environmental stress in early life is predicted to have been favoured by natural selection. This vulnerability is most evident in the harsh conditions resulting from pre-term birth, but can also be seen in term infants, and manifests as greater morbidity and mortality persisting into early childhood. Malnutrition, interacting with infection after birth, is suggested as the fundamental trigger mechanism. The model suggests that whatever improvements are made in medical care, any environmental stress will always affect males more severely than females in early life. Copyright 2000 Academic Press.

The nature of selection on the major histocompatibility complex.

PubMed

Apanius, V; Penn, D; Slev, P R; Ruff, L R; Potts, W K

1997-01-01

Only natural selection can account for the extreme genetic diversity of genes of the major histocompatibility complex (MHC). Although the structure and function of classic MHC genes is well understood at the molecular and cellular levels, there is controversy about how MHC diversity is selectively maintained. The diversifying selection can be driven by pathogen interactions and inbreeding avoidance mechanisms. Pathogen-driven selection can maintain MHC polymorphism based on heterozygote advantage or frequency-dependent selection due to pathogen evasion of MHC-dependent immune recognition. Empirical evidence demonstrates that specific MHC haplotypes are resistant to certain infectious agents, while susceptible to others. These data are consistent with both heterozygote advantage and frequency-dependent models. Additional research is needed to discriminate between these mechanisms. Infectious agents can precipitate autoimmunity and can potentially contribute to MHC diversity through molecular mimicry and by favoring immunodominance. MHC-dependent abortion and mate choice, based on olfaction, can also maintain MHC diversity and probably functions both to avoid genome-wide inbreeding and produce MHC-heterozygous offspring with increased immune responsiveness. Although this diverse set of hypotheses are often treated as competing alternatives, we believe that they all fit into a coherent, internally consistent thesis. It is likely that at least in some species, all of these mechanisms operate, leading to the extreme diversification found in MHC genes.

Natural and sexual selection giveth and taketh away reproductive barriers: models of population divergence in guppies.

PubMed

Labonne, Jacques; Hendry, Andrew P

2010-07-01

The standard predictions of ecological speciation might be nuanced by the interaction between natural and sexual selection. We investigated this hypothesis with an individual-based model tailored to the biology of guppies (Poecilia reticulata). We specifically modeled the situation where a high-predation population below a waterfall colonizes a low-predation population above a waterfall. Focusing on the evolution of male color, we confirm that divergent selection causes the appreciable evolution of male color within 20 generations. The rate and magnitude of this divergence were reduced when dispersal rates were high and when female choice did not differ between environments. Adaptive divergence was always coupled to the evolution of two reproductive barriers: viability selection against immigrants and hybrids. Different types of sexual selection, however, led to contrasting results for another potential reproductive barrier: mating success of immigrants. In some cases, the effects of natural and sexual selection offset each other, leading to no overall reproductive isolation despite strong adaptive divergence. Sexual selection acting through female choice can thus strongly modify the effects of divergent natural selection and thereby alter the standard predictions of ecological speciation. We also found that under no circumstances did divergent selection cause appreciable divergence in neutral genetic markers.

Selecting the Best Mobile Information Service with Natural Language User Input

NASA Astrophysics Data System (ADS)

Feng, Qiangze; Qi, Hongwei; Fukushima, Toshikazu

Information services accessed via mobile phones provide information directly relevant to subscribers’ daily lives and are an area of dynamic market growth worldwide. Although many information services are currently offered by mobile operators, many of the existing solutions require a unique gateway for each service, and it is inconvenient for users to have to remember a large number of such gateways. Furthermore, the Short Message Service (SMS) is very popular in China and Chinese users would prefer to access these services in natural language via SMS. This chapter describes a Natural Language Based Service Selection System (NL3S) for use with a large number of mobile information services. The system can accept user queries in natural language and navigate it to the required service. Since it is difficult for existing methods to achieve high accuracy and high coverage and anticipate which other services a user might want to query, the NL3S is developed based on a Multi-service Ontology (MO) and Multi-service Query Language (MQL). The MO and MQL provide semantic and linguistic knowledge, respectively, to facilitate service selection for a user query and to provide adaptive service recommendations. Experiments show that the NL3S can achieve 75-95% accuracies and 85-95% satisfactions for processing various styles of natural language queries. A trial involving navigation of 30 different mobile services shows that the NL3S can provide a viable commercial solution for mobile operators.

Population genetic structure and natural selection of Plasmodium falciparum apical membrane antigen-1 in Myanmar isolates.

PubMed

Kang, Jung-Mi; Lee, Jinyoung; Moe, Mya; Jun, Hojong; Lê, Hương Giang; Kim, Tae Im; Thái, Thị Lam; Sohn, Woon-Mok; Myint, Moe Kyaw; Lin, Khin; Shin, Ho-Joon; Kim, Tong-Soo; Na, Byoung-Kuk

2018-02-07

Plasmodium falciparum apical membrane antigen-1 (PfAMA-1) is one of leading blood stage malaria vaccine candidates. However, genetic variation and antigenic diversity identified in global PfAMA-1 are major hurdles in the development of an effective vaccine based on this antigen. In this study, genetic structure and the effect of natural selection of PfAMA-1 among Myanmar P. falciparum isolates were analysed. Blood samples were collected from 58 Myanmar patients with falciparum malaria. Full-length PfAMA-1 gene was amplified by polymerase chain reaction and cloned into a TA cloning vector. PfAMA-1 sequence of each isolate was sequenced. Polymorphic characteristics and effect of natural selection were analysed with using DNASTAR, MEGA4, and DnaSP programs. Polymorphic nature and natural selection in 459 global PfAMA-1 were also analysed. Thirty-seven different haplotypes of PfAMA-1 were identified in 58 Myanmar P. falciparum isolates. Most amino acid changes identified in Myanmar PfAMA-1 were found in domains I and III. Overall patterns of amino acid changes in Myanmar PfAMA-1 were similar to those in global PfAMA-1. However, frequencies of amino acid changes differed by country. Novel amino acid changes in Myanmar PfAMA-1 were also identified. Evidences for natural selection and recombination event were observed in global PfAMA-1. Among 51 commonly identified amino acid changes in global PfAMA-1 sequences, 43 were found in predicted RBC-binding sites, B-cell epitopes, or IUR regions. Myanmar PfAMA-1 showed similar patterns of nucleotide diversity and amino acid polymorphisms compared to those of global PfAMA-1. Balancing natural selection and intragenic recombination across PfAMA-1 are likely to play major roles in generating genetic diversity in global PfAMA-1. Most common amino acid changes in global PfAMA-1 were located in predicted B-cell epitopes where high levels of nucleotide diversity and balancing natural selection were found. These results highlight the

Reasoning about Natural Selection: Diagnosing Contextual Competency Using the ACORNS Instrument

ERIC Educational Resources Information Center

Nehm, Ross H.; Beggrow, Elizabeth P.; Opfer, John E.; Ha, Minsu

2012-01-01

Studies of students' thinking about natural selection have revealed that the scenarios in which students reason evoke different types, magnitudes, and arrangements of knowledge elements and misconceptions. Diagnostic tests are needed that probe students' thinking across a representative array of evolutionary contexts. The ACORNS is a diagnostic…

Solidarity with Animals: Assessing a Relevant Dimension of Social Identification with Animals.

PubMed

Amiot, Catherine E; Bastian, Brock

2017-01-01

Interactions with animals are pervasive in human life, a fact that is reflected in the burgeoning field of human-animal relations research. The goal of the current research was to examine the psychology of our social connection with other animals, by specifically developing a measure of solidarity with animals. In 8 studies using correlational, experimental, and longitudinal designs, solidarity with animals predicted more positive attitudes and behaviors toward animals, over and above existing scales of identification, and even when this implied a loss of resources and privileges for humans relative to animals. Solidarity with animals also displayed predicted relationships with relevant variables (anthropomorphism, empathy). Pet owners and vegetarians displayed higher levels of solidarity with animals. Correlational and experimental evidence confirmed that human-animal similarity heightens solidarity with animals. Our findings provide a useful measure that can facilitate important insights into the nature of our relationships with animals.

Solidarity with Animals: Assessing a Relevant Dimension of Social Identification with Animals

PubMed Central

Amiot, Catherine E.; Bastian, Brock

2017-01-01

Interactions with animals are pervasive in human life, a fact that is reflected in the burgeoning field of human-animal relations research. The goal of the current research was to examine the psychology of our social connection with other animals, by specifically developing a measure of solidarity with animals. In 8 studies using correlational, experimental, and longitudinal designs, solidarity with animals predicted more positive attitudes and behaviors toward animals, over and above existing scales of identification, and even when this implied a loss of resources and privileges for humans relative to animals. Solidarity with animals also displayed predicted relationships with relevant variables (anthropomorphism, empathy). Pet owners and vegetarians displayed higher levels of solidarity with animals. Correlational and experimental evidence confirmed that human-animal similarity heightens solidarity with animals. Our findings provide a useful measure that can facilitate important insights into the nature of our relationships with animals. PMID:28045909

Flexible Animation Computer Program

NASA Technical Reports Server (NTRS)

Stallcup, Scott S.

1990-01-01

FLEXAN (Flexible Animation), computer program animating structural dynamics on Evans and Sutherland PS300-series graphics workstation with VAX/VMS host computer. Typical application is animation of spacecraft undergoing structural stresses caused by thermal and vibrational effects. Displays distortions in shape of spacecraft. Program displays single natural mode of vibration, mode history, or any general deformation of flexible structure. Written in FORTRAN 77.

No Evidence for Natural Selection on Endogenous Borna-Like Nucleoprotein Elements after the Divergence of Old World and New World Monkeys

PubMed Central

Kobayashi, Yuki; Horie, Masayuki; Tomonaga, Keizo; Suzuki, Yoshiyuki

2011-01-01

Endogenous Borna-like nucleoprotein (EBLNs) elements were recently discovered as non-retroviral RNA virus elements derived from bornavirus in the genomes of various animals. Most of EBLNs appeared to be defective, but some of primate EBLN-1 to -4, which appeared to be originated from four independent integrations of bornavirus nucleoprotein (N) gene, have retained an open reading frame (ORF) for more than 40 million years. It was therefore possible that primate EBLNs have encoded functional proteins during evolution. To examine this possibility, natural selection operating on all ORFs of primate EBLN-1 to -4 was examined by comparing the rates of synonymous and nonsynonymous substitutions. The expected number of premature termination codons in EBLN-1 generated after the divergence of Old World and New World monkeys under the selective neutrality was also examined by the Monte Carlo simulation. As a result, natural selection was not identified for the entire region as well as parts of ORFs in the pairwise analysis of primate EBLN-1 to -4 and for any branch of the phylogenetic trees for EBLN-1 to -4 after the divergence of Old World and New World monkeys. Computer simulation also indicated that the absence of premature termination codon in the present-day EBLN-1 does not necessarily support the maintenance of function after the divergence of Old World and New World monkeys. These results suggest that EBLNs have not generally encoded functional proteins after the divergence of Old World and New World monkeys. PMID:21912690

The Nature of Selection and Judging for the Teacher of the Year Award.

ERIC Educational Resources Information Center

McKenna, Bonnie; And Others

This paper reports on the investigation of the operation of the Teacher of the Year Award program in 28 states. It focuses on the method of selection for recipients of this award, and explores the nature of the judging process used in selecting candidates at both the state and national levels. Specific objectives are: (1) to determine the criteria…

Mice selected for high versus low stress reactivity: a new animal model for affective disorders.

PubMed

Touma, Chadi; Bunck, Mirjam; Glasl, Lisa; Nussbaumer, Markus; Palme, Rupert; Stein, Hendrik; Wolferstätter, Michael; Zeh, Ramona; Zimbelmann, Marina; Holsboer, Florian; Landgraf, Rainer

2008-07-01

Affective disorders such as major depression are among the most prevalent and costly diseases of the central nervous system, but the underlying mechanisms are still poorly understood. In recent years, it has become evident that alterations of the stress hormone system, in particular dysfunctions (hyper- or hypo-activity) of the hypothalamic-pituitary-adrenal (HPA) axis, play a prominent role in the development of major depressive disorders. Therefore, we aimed to generate a new animal model comprising these neuroendocrine core symptoms in order to unravel parameters underlying increased or decreased stress reactivity. Starting from a population of outbred mice (parental generation: 100 males and 100 females of the CD-1 strain), two breeding lines were established according to the outcome of a 'stress reactivity test' (SRT), consisting of a 15-min restraint period and tail blood samplings immediately before and after exposure to the stressor. Mice showing a very high or a very low secretion of corticosterone in the SRT, i.e. animals expressing a hyper- or a hypo-reactivity of the HPA axis, were selected for the 'high reactivity' (HR) and the 'low reactivity' (LR) breeding line, respectively. Additionally, a third breeding line was established consisting of animals with an 'intermediate reactivity' (IR) in the SRT. Already in the first generation, i.e. animals derived from breeding pairs selected from the parental generation, significant differences in the reactivity of the HPA axis between HR, IR, and LR mice were observed. Moreover, these differences were found across all subsequent generations and could be increased by selective breeding, which indicates a genetic basis of the respective phenotype. Repeated testing of individuals in the SRT furthermore proved that the observed differences in stress responsiveness are present already early in life and can be regarded as a robust genetic predisposition. Tests investigating the animal's emotionality including anxiety

An admissions system to select veterinary medical students with an interest in food animals and veterinary public health.

PubMed

Haarhuis, Jan C M; Muijtjens, Arno M M; Scherpbier, Albert J J A; van Beukelen, Peter

2009-01-01

Interest in the areas of food animals (FA) and veterinary public health (VPH) appears to be declining among prospective students of veterinary medicine. To address the expected shortage of veterinarians in these areas, the Utrecht Faculty of Veterinary Medicine has developed an admissions procedure to select undergraduates whose aptitude and interests are suited to these areas. A study using expert meetings, open interviews, and document analysis identified personal characteristics that distinguished veterinarians working in the areas of FA and VPH from their colleagues who specialized in companion animals (CA) and equine medicine (E). The outcomes were used to create a written selection tool. We validated this tool in a study among undergraduate veterinary students in their final (sixth) year before graduation. The applicability of the tool was verified in a study among first-year students who had opted to pursue either FA/VPH or CA/E. The tool revealed statistically significant differences with acceptable effect sizes between the two student groups. Because the written selection tool did not cover all of the differences between the veterinarians who specialized in FA/VPH and those who specialized in CA/E, we developed a prestructured panel interview and added it to the questionnaire. The evaluation of the written component showed that it was suitable for selecting those students who were most likely to succeed in the FA/VPH track.

Does the Animal Welfare Act apply to free-ranging animals?

USGS Publications Warehouse

Mulcahy, Daniel M.

2003-01-01

Despite the long-standing role that institutional animal care and use committees (IACUCs) have played in reviewing and approving studies at academic institutions, compliance with the Animal Welfare Act (AWA) is not always complete for government natural resource agencies that use free-ranging animals in research and management studies. Even at universities, IACUCs face uncertainties about what activities are covered and about how to judge proposed research on free-ranging animals. One reason for much of the confusion is the AWA vaguely worded exemption for "field studies." In particular, fish are problematic because of the AWA exclusion of poikilothermic animals. However, most university IACUCs review studies on all animals, and the Interagency Research Animal Committee (IRAC) has published the "IRAC Principles," which extend coverage to all vertebrates used by federal researchers. Despite this extended coverage, many scientists working on wild animals continue to view compliance with the AWA with little enthusiasm. IACUCs, IACUC veterinarians, wildlife veterinarians, and fish and wildlife biologists must learn to work together to comply with the law and to protect the privilege of using free-ranging animals in research.

Divergent Human Cortical Regions for Processing Distinct Acoustic-Semantic Categories of Natural Sounds: Animal Action Sounds vs. Vocalizations

PubMed Central

Webster, Paula J.; Skipper-Kallal, Laura M.; Frum, Chris A.; Still, Hayley N.; Ward, B. Douglas; Lewis, James W.

2017-01-01

A major gap in our understanding of natural sound processing is knowledge of where or how in a cortical hierarchy differential processing leads to categorical perception at a semantic level. Here, using functional magnetic resonance imaging (fMRI) we sought to determine if and where cortical pathways in humans might diverge for processing action sounds vs. vocalizations as distinct acoustic-semantic categories of real-world sound when matched for duration and intensity. This was tested by using relatively less semantically complex natural sounds produced by non-conspecific animals rather than humans. Our results revealed a striking double-dissociation of activated networks bilaterally. This included a previously well described pathway preferential for processing vocalization signals directed laterally from functionally defined primary auditory cortices to the anterior superior temporal gyri, and a less well-described pathway preferential for processing animal action sounds directed medially to the posterior insulae. We additionally found that some of these regions and associated cortical networks showed parametric sensitivity to high-order quantifiable acoustic signal attributes and/or to perceptual features of the natural stimuli, such as the degree of perceived recognition or intentional understanding. Overall, these results supported a neurobiological theoretical framework for how the mammalian brain may be fundamentally organized to process acoustically and acoustic-semantically distinct categories of ethologically valid, real-world sounds. PMID:28111538

Natural infection by endoparasites among free-living wild animals.

PubMed

Holsback, Luciane; Cardoso, Mauro José Lahm; Fagnani, Rafael; Patelli, Thaís Helena Constantino

2013-01-01

The objective of this study was to investigate the frequency of occurrence and variety of intestinal parasites among free-living wild animals. Fecal samples from wild mammals and birds at rehabilitation centers in the states of Mato Grosso do Sul and São Paulo were analyzed by sedimentation and flotation-centrifugation methods. Parasite eggs, oocysts, cysts and/or trophozoites were found in 71% of the samples. Cryptosporidium sp. oocysts were detected in fecal samples from oncillas (Leopardus tigrinus) and scaly-headed parrots (Pionus maximiliani). Giardia cysts were identified in the feces of a gray brocket (Mazama gouazoubira). Among the most common parasites found, there were eggs from Toxocara cati, Toxascaris leonina and Ancylostoma tubaeforme, and from Cestoda. Several Enterobius sp. eggs were found in the feces of red howler monkeys (Alouatta seniculus). It can be concluded from this study that despite the small number of samples, the diversity of parasites found was noteworthy. Additional information about parasite endofauna in wild animals is needed, since their presence might suggest that there could be proximity to and interactions with domestic animals and/or humans. In addition, further studies on parasites from free-living wild animals are of prime importance for understanding the intensity of anthropic changes in wild environments.

An experimental demonstration of Fisher's principle: evolution of sexual proportion by natural selection.

PubMed Central

Carvalho, A B; Sampaio, M C; Varandas, F R; Klaczko, L B

1998-01-01

Most sexually reproducing species have sexual proportions around 1:1. This major biological phenomenon remained unexplained until 1930, when FISHER proposed that it results from a mechanism of natural selection. Here we report the first experimental test of his model that obeys all its assumptions. We used a naturally occurring X-Y meiotic drive system--the sex-ratio trait of Drosophila mediopunctat--to generate female-biased experimental populations. As predicted by FISHER, these populations evolved toward equal sex proportions due to natural selection, by accumulation of autosomal alleles that direct the parental reproductive effort toward the rare sex. Classical Fisherian evolution is a rather slow mechanism: despite a very large amount of genetic variability, the experimental populations evolved from 16% of males to 32% of males in 49 generations and would take 330 generations (29 years) to reach 49%. This slowness has important implications for species potentially endangered by skewed sexual proportions, such as reptiles with temperature sex determination. PMID:9504919

Estimating selection through male fitness: three complementary methods illuminate the nature and causes of selection on flowering time

PubMed Central

Austen, Emily J.; Weis, Arthur E.

2016-01-01

Our understanding of selection through male fitness is limited by the resource demands and indirect nature of the best available genetic techniques. Applying complementary, independent approaches to this problem can help clarify evolution through male function. We applied three methods to estimate selection on flowering time through male fitness in experimental populations of the annual plant Brassica rapa: (i) an analysis of mating opportunity based on flower production schedules, (ii) genetic paternity analysis, and (iii) a novel approach based on principles of experimental evolution. Selection differentials estimated by the first method disagreed with those estimated by the other two, indicating that mating opportunity was not the principal driver of selection on flowering time. The genetic and experimental evolution methods exhibited striking agreement overall, but a slight discrepancy between the two suggested that negative environmental covariance between age at flowering and male fitness may have contributed to phenotypic selection. Together, the three methods enriched our understanding of selection on flowering time, from mating opportunity to phenotypic selection to evolutionary response. The novel experimental evolution method may provide a means of examining selection through male fitness when genetic paternity analysis is not possible. PMID:26911957

Laboratory Animal Facilities. Laboratory Design Notes.

ERIC Educational Resources Information Center

Jonas, Albert M.

1965-01-01

Design of laboratory animal facilities must be functional. Accordingly, the designer should be aware of the complex nature of animal research and specifically the type of animal research which will be conducted in a new facility. The building of animal-care facilities in research institutions requires special knowledge in laboratory animal…

Selective Determination of Lipid Hydroperoxides in Natural Waters Using a Fluorescent Probe

NASA Astrophysics Data System (ADS)

Sunday, M. O.; Sakugawa, H.

2016-12-01

The presence of various lipids in natural waters and the availability of conditions needed for their oxidation to lipid hydroperoxides (LHPs) suggest that LHPs may be part of the hydroperoxide mix in natural waters. While other hydroperoxides, including H2O2, methyl hydroperoxide (MHP) and ethyl hydroperoxide (EHP) etc. have been investigated, there is no information on LHPs in natural waters. In this study, we report the presence of LHPs in natural waters. Firstly, a method selective to LHPs determination was developed using 2-(4-diphenylphosphanyl-phenyl)-9-(3,6,9,12-tetraoxatridecyl)-anthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline-1,3,8,10-tetraone, Liperfluo, as a fluorescent probe. A flow injector analysis equipped with fluorescence detector was used for fluorescence measurement of Liperfluo-Ox formed from the reaction between Liperfluo and LHP. Under the optimized conditions, the reaction of Liperfluo with LHP in MilliQ and river water had a linear range of 0-500 nM LHP. The method detection limit was 10.1 nM and 7.3 nM in riverwater and MilliQ respectively. The coefficient of variation for five replicate measurements each for 100 nM and 500 nM LHP was ≤ 3.8%. The probe and the conditions used in this study showed high selectivity for LHP over other natural water hydroperoxides, including H2O2, MHP and EHP. The method was applied in the quantification of LHPs in water from the Kurose River (Japan). The concentration ranged from below detection limit to 98 nM (ave. 37.2 nM; n=12). Increase in H2O2 formation upon irradiation of LHP-spiked riverwater in a solar simulator suggests H2O2 formation as one of the possible sinks of LHPs in natural waters. For the first time, this study reveals that LHPs are part of the hydroperoxide mix in natural waters and provides insight on its fate in natural waters.

Greetings from the Animal Kingdom.

ERIC Educational Resources Information Center

Kramer, David C.

1990-01-01

Described is a classification activity that uses holiday greeting cards. Identification of animals, their characteristics, natural habitat, eating patterns, and geography are some of the suggested ways in which to classify the animals. (KR)

Warning signals are under positive frequency-dependent selection in nature

PubMed Central

Chouteau, Mathieu; Arias, Mónica; Joron, Mathieu

2016-01-01

Positive frequency-dependent selection (FDS) is a selection regime where the fitness of a phenotype increases with its frequency, and it is thought to underlie important adaptive strategies resting on signaling and communication. However, whether and how positive FDS truly operates in nature remains unknown, which hampers our understanding of signal diversity. Here, we test for positive FDS operating on the warning color patterns of chemically defended butterflies forming multiple coexisting mimicry assemblages in the Amazon. Using malleable prey models placed in localities showing differences in the relative frequencies of warningly colored prey, we demonstrate that the efficiency of a warning signal increases steadily with its local frequency in the natural community, up to a threshold where protection stabilizes. The shape of this relationship is consistent with the direct effect of the local abundance of each warning signal on the corresponding avoidance knowledge of the local predator community. This relationship, which differs from purifying selection acting on each mimetic pattern, indicates that predator knowledge, integrated over the entire community, is saturated only for the most common warning signals. In contrast, among the well-established warning signals present in local prey assemblages, most are incompletely known to local predators and enjoy incomplete protection. This incomplete predator knowledge should generate strong benefits to life history traits that enhance warning efficiency by increasing the effective frequency of prey visible to predators. Strategies such as gregariousness or niche convergence between comimics may therefore readily evolve through their effects on predator knowledge and warning efficiency. PMID:26858416

Ticks and tick-borne novel bunyavirus collected from the natural environment and domestic animals in Jinan city, East China.

PubMed

Wang, Dong; Wang, Yongming; Yang, Guoliang; Liu, Huiyuan; Xin, Zheng

2016-02-01

Since 2011, 73 cases of the severe fever with thrombocytopenia syndrome, a novel tick-borne disease, have been reported in Jinan city through information system for disease control and prevention. Therefore, this study aimed to investigate the species, distribution, host animals of ticks and tick-borne pathogens. A total of 722 ticks were collected from two types of natural environment and six kinds of domestic animal in Jinan city. All the sampled ticks belonged to the same species, namely Haemaphysalis longicornis, and 94.7% of them were adult. The density of free-living ticks in grassland was nearly six times that in shrub. The prevalence of the goat (53.3%) was highest among the domestic animals. The host body region most frequently parasitized by H. longicornis was the head (77.8%), especially ears and periocular region. Novel bunyavirus was detected on the free-ranging goats in Jinan city. Acaricide treatment with a higher concentration on the ears, periocular region and the groin of domestic animals should be recommended to control the ticks effectively.

Trends in animal experimentation.

PubMed

Monteiro, Rosangela; Brandau, Ricardo; Gomes, Walter J; Braile, Domingo M

2009-01-01

The search of the understanding of etiological factors, mechanisms and treatment of the diseases has been taking to the development of several animal models in the last decades. To discuss aspects related to animal models of experimentation, animal choice and current trends in this field in our country. In addition, this study evaluated the frequency of experimental articles in medical journals. Five Brazilian journals indexed by LILACS, SciELO, MEDLINE, and recently incorporate for Institute for Scientific Information Journal of Citation Reports were analyzed. All the papers published in those journals, between 2007 and 2008, that used animal models, were selected based on the abstracts. Of the total of 832 articles published in the period, 92 (11.1%) experimentation papers were selected. The number of experimental articles ranged from 5.2% to 17.9% of the global content of the journal. In the instructions to the authors, four (80%) journals presented explicit reference to the ethical principles in the conduction of studies with animals. The induced animal models represented 100% of the articles analyzed in this study. The rat was the most employed animal in the analyzed articles (78.3%). The present study can contribute, supplying subsidies for adoption of future editorials policies regarding the publication of animal research papers in Brazilian Journal of Cardiovascular Surgery.

[Animals and environmentalist ethics].

PubMed

Guichet, Jean-Luc

2013-01-01

While environmental ethics and animal ethics have a common source of inspiration, they do not agree on the question of the status of animals. Environmental ethicists criticise the narrowness of the reason, focused on pain, given by animal ethicists and their strictly individual point of view; they maintain that their ethical concept is less emotional and more informed by science, with a broad point of view taking natural networks into account. Animal ethicists respond critically, accusing the environmental ethicists of not having any ethical foundation. There are, however, prospects for reconciling the two approaches, provided that they recognise two different ethical stances for animals: one based on the integrity of wild animals and the other based on a model contract for tame animals.

All about Endangered and Extinct Animals. Animal Life for Children. [Videotape].

ERIC Educational Resources Information Center

2000

While there are thousands of different animals in the world, some have been extinct for many years and others are on the verge of extinction. In this videotape, students learn about the natural and man-made factors that lead to the endangerment and extinction of animals. Children find out why it is essential for people to help all forms of…

A Selective Critique of Animal Experiments in Human-Orientated Biological Research.

ERIC Educational Resources Information Center

Webb, G. P.

1990-01-01

The advantages and justifications for using small animals in human-oriented research are reviewed. Some of the pitfalls of extrapolating animal-derived data to humans are discussed. Several specific problems with animal experimentation are highlighted. (CW)

Disease Risk Assessments Involving Companion Animals: an Overview for 15 Selected Pathogens Taking a European Perspective.

PubMed

Rijks, J M; Cito, F; Cunningham, A A; Rantsios, A T; Giovannini, A

2016-07-01

Prioritization of companion animal transmissible diseases was performed by the Companion Animals multisectoriaL interprofessionaL Interdisciplinary Strategic Think tank On zoonoses (CALLISTO) project. The project considered diseases occurring in domesticated species commonly kept as pets, such as dogs and cats, but also included diseases occurring in captive wild animals and production animal species. The prioritization process led to the selection of 15 diseases of prime public health relevance, agricultural economic importance, or both. An analysis was made of the current knowledge on the risk of occurrence and transmission of these diseases among companion animals, and from companion animals to man (zoonoses) or to livestock. The literature was scanned for risk assessments for these diseases. Studies were classified as import risk assessments (IRAs) or risk factor analyses (RFAs) in endemic areas. For those pathogens that are absent from Europe, only IRAs were considered; for pathogens present throughout Europe, only RFAs were considered. IRAs were identified for seven of the eight diseases totally or partially absent from Europe. IRAs for classical rabies and alveolar echinococcosis found an increased risk for introduction of the pathogen into officially disease-free areas as a consequence of abandoning national rules and adopting the harmonized EU rules for pet travel. IRAs for leishmaniosis focused on risk associated with the presence of persistently infected dogs in new geographical areas, taking into consideration the risk of disease establishment should a competent vector arise. IRAs for Crimean-Congo haemorrhagic fever and West Nile fever indicated that the likelihood of introduction via companion animals was low. IRAs for bluetongue paid no attention to the risk of introduction via companion animals, which was also the case for IRAs for foot-and-mouth disease, the only disease considered to be absent from Europe. RFAs dealing with the risk factors for

Goal-Side Selection in Soccer Penalty Kicking When Viewing Natural Scenes

PubMed Central

Weigelt, Matthias; Memmert, Daniel

2012-01-01

The present study investigates the influence of goalkeeper displacement on goal-side selection in soccer penalty kicking. Facing a penalty situation, participants viewed photo-realistic images of a goalkeeper and a soccer goal. In the action selection task, they were asked to kick to the greater goal-side, and in the perception task, they indicated the position of the goalkeeper on the goal line. To this end, the goalkeeper was depicted in a regular goalkeeping posture, standing either in the exact middle of the goal or being displaced at different distances to the left or right of the goal’s center. Results showed that the goalkeeper’s position on the goal line systematically affected goal-side selection, even when participants were not aware of the displacement. These findings provide further support for the notion that the implicit processing of the stimulus layout in natural scenes can effect action selection in complex environments, such in soccer penalty shooting. PMID:22973246

Natural selection and the predictability of evolution in Timema stick insects.

PubMed

Nosil, Patrik; Villoutreix, Romain; de Carvalho, Clarissa F; Farkas, Timothy E; Soria-Carrasco, Víctor; Feder, Jeffrey L; Crespi, Bernard J; Gompert, Zach

2018-02-16

Predicting evolution remains difficult. We studied the evolution of cryptic body coloration and pattern in a stick insect using 25 years of field data, experiments, and genomics. We found that evolution is more difficult to predict when it involves a balance between multiple selective factors and uncertainty in environmental conditions than when it involves feedback loops that cause consistent back-and-forth fluctuations. Specifically, changes in color-morph frequencies are modestly predictable through time ( r 2 = 0.14) and driven by complex selective regimes and yearly fluctuations in climate. In contrast, temporal changes in pattern-morph frequencies are highly predictable due to negative frequency-dependent selection ( r 2 = 0.86). For both traits, however, natural selection drives evolution around a dynamic equilibrium, providing some predictability to the process. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Look Past the Stuffed Animals and Learn about the Earth: Dioramas at the American Museum of Natural History

NASA Astrophysics Data System (ADS)

Passow, M. J.

2017-12-01

The dioramas at the American Museum of Natural History (AMNH) in New York City provide great examples of artwork depicting locations of interest and value for teaching the Earth Sciences. When the Museum was established in 1869, it—like most institutions of that time—merely provided a taxidermy collection in cases. But as it expanded into the dozens of Halls in its multiple public buildings, curators made a deliberate effort to display the specimens with backdrops depicting the habitats where the animals were collected. Such `curatorial giants' as Frank Chapman and Carl Ackley spearheaded pioneering efforts to present displays in the curved, framed settings. The impact of these large- and small-scale artworks on the Public cannot be underestimated. Instead of just viewing the remains of a dead animal, visitors are transported around the world into a wide variety of ecosystems. With no more effort than walking from one display to the next, viewers "magically travel" to the multitude of environments across Planet Earth. The dioramas may take one from mountaintop vistas to the microsystem just a few centimeters above and below the forest floor. This presentation will provide selected examples of the artwork in AMNH dioramas. The AMNH website provides numerous videos and posts about its dioramas. I will also provide insights into the creation of more recent artwork using an online interview with Sean Murtha, the artist who created many of the Hall of Ocean Life dioramas. Predating modern technologies, including color photography, television, and computers, these dioramas are rightly described as powerful tools for nurturing scientific education and environmental awareness. These dioramas frequently are utilized to teach important Earth System Science concepts to school groups and other visitors, and examples of such lessons will be included.

Interaction-based evolution: how natural selection and nonrandom mutation work together.

PubMed

Livnat, Adi

2013-10-18

The modern evolutionary synthesis leaves unresolved some of the most fundamental, long-standing questions in evolutionary biology: What is the role of sex in evolution? How does complex adaptation evolve? How can selection operate effectively on genetic interactions? More recently, the molecular biology and genomics revolutions have raised a host of critical new questions, through empirical findings that the modern synthesis fails to explain: for example, the discovery of de novo genes; the immense constructive role of transposable elements in evolution; genetic variance and biochemical activity that go far beyond what traditional natural selection can maintain; perplexing cases of molecular parallelism; and more. Here I address these questions from a unified perspective, by means of a new mechanistic view of evolution that offers a novel connection between selection on the phenotype and genetic evolutionary change (while relying, like the traditional theory, on natural selection as the only source of feedback on the fit between an organism and its environment). I hypothesize that the mutation that is of relevance for the evolution of complex adaptation-while not Lamarckian, or "directed" to increase fitness-is not random, but is instead the outcome of a complex and continually evolving biological process that combines information from multiple loci into one. This allows selection on a fleeting combination of interacting alleles at different loci to have a hereditary effect according to the combination's fitness. This proposed mechanism addresses the problem of how beneficial genetic interactions can evolve under selection, and also offers an intuitive explanation for the role of sex in evolution, which focuses on sex as the generator of genetic combinations. Importantly, it also implies that genetic variation that has appeared neutral through the lens of traditional theory can actually experience selection on interactions and thus has a much greater adaptive

Interaction-based evolution: how natural selection and nonrandom mutation work together

PubMed Central

2013-01-01

Background The modern evolutionary synthesis leaves unresolved some of the most fundamental, long-standing questions in evolutionary biology: What is the role of sex in evolution? How does complex adaptation evolve? How can selection operate effectively on genetic interactions? More recently, the molecular biology and genomics revolutions have raised a host of critical new questions, through empirical findings that the modern synthesis fails to explain: for example, the discovery of de novo genes; the immense constructive role of transposable elements in evolution; genetic variance and biochemical activity that go far beyond what traditional natural selection can maintain; perplexing cases of molecular parallelism; and more. Presentation of the hypothesis Here I address these questions from a unified perspective, by means of a new mechanistic view of evolution that offers a novel connection between selection on the phenotype and genetic evolutionary change (while relying, like the traditional theory, on natural selection as the only source of feedback on the fit between an organism and its environment). I hypothesize that the mutation that is of relevance for the evolution of complex adaptation—while not Lamarckian, or “directed” to increase fitness—is not random, but is instead the outcome of a complex and continually evolving biological process that combines information from multiple loci into one. This allows selection on a fleeting combination of interacting alleles at different loci to have a hereditary effect according to the combination’s fitness. Testing and implications of the hypothesis This proposed mechanism addresses the problem of how beneficial genetic interactions can evolve under selection, and also offers an intuitive explanation for the role of sex in evolution, which focuses on sex as the generator of genetic combinations. Importantly, it also implies that genetic variation that has appeared neutral through the lens of traditional

Repertoire of BALB/c Mice Natural Anti-Carbohydrate Antibodies: Mice vs. Humans Difference, and Otherness of Individual Animals

PubMed Central

Bello-Gil, Daniel; Khasbiullina, Nailya; Shilova, Nadezhda; Bovin, Nicolai; Mañez, Rafael

2017-01-01

One of the most common genetic backgrounds for mice used as a model to investigate human diseases is the inbred BALB/c strain. This work is aimed to characterize the pattern of natural anti-carbohydrate antibodies present in the serum of 20 BALB/c mice by printed glycan array technology and to compare their binding specificities with that of human natural anti-carbohydrate antibodies. Natural antibodies (NAbs) from the serum of BALB/c mice interacted with 71 glycans from a library of 419 different carbohydrate structures. However, only seven of these glycans were recognized by the serum of all the animals studied, and other five glycans by at least 80% of mice. The pattern of the 12 glycans mostly recognized by the circulating antibodies of BALB/c mice differed significantly from that observed with natural anti-carbohydrate antibodies in humans. This lack of identical repertoires of natural anti-carbohydrate antibodies between individual inbred mice, and between mice and humans, should be taken into consideration when mouse models are intended to be used for investigation of NAbs in biomedical research. PMID:29163519

[The metaphysical dimension of animal ethics].

PubMed

Walz, Norbert

2008-01-01

Utilitarian ethics recognises animals as moral objects, but it does not attribute an absolute value to human or non-human individuals. Animal ethics according to Regan defines the non-human individual as an inherent value, but concedes that humans should be given precedence over animals if a situation involves a decision between life and death. Such life and death decisions relate to the fundamental structures of biological nature. To individuals these fundamental structures (the paradox of life and death) will necessarily appear absurd. The metaphysical dimension of animal ethics tries to shed light on the connections between life and death, body and mind that underly ethical discussions and searches for alternatives to the natural organisation of life.

Darwin's Arguments in Favour of Natural Selection and against Special Creationism

ERIC Educational Resources Information Center

Nola, Robert

2013-01-01

In many places in "The Origin of Species", Darwin compares his own theory of Natural Selection favourably with Special Creationism which comes off as a bad second best. He does this using some version of the argument form known as "Inference to the Best Explanation". The first part of this paper is methodological. It considers Whewell's notion of…

How can we estimate natural selection on endocrine traits? Lessons from evolutionary biology

PubMed Central

2016-01-01

An evolutionary perspective can enrich almost any endeavour in biology, providing a deeper understanding of the variation we see in nature. To this end, evolutionary endocrinologists seek to describe the fitness consequences of variation in endocrine traits. Much of the recent work in our field, however, follows a flawed approach to the study of how selection shapes endocrine traits. Briefly, this approach relies on among-individual correlations between endocrine phenotypes (often circulating hormone levels) and fitness metrics to estimate selection on those endocrine traits. Adaptive plasticity in both endocrine and fitness-related traits can drive these correlations, generating patterns that do not accurately reflect natural selection. We illustrate why this approach to studying selection on endocrine traits is problematic, referring to work from evolutionary biologists who, decades ago, described this problem as it relates to a variety of other plastic traits. We extend these arguments to evolutionary endocrinology, where the likelihood that this flaw generates bias in estimates of selection is unusually high due to the exceptional responsiveness of hormones to environmental conditions, and their function to induce adaptive life-history responses to environmental variation. We end with a review of productive approaches for investigating the fitness consequences of variation in endocrine traits that we expect will generate exciting advances in our understanding of endocrine system evolution. PMID:27881753

Novel peptide chemistry in terrestrial animals: natural luciferin analogues from the bioluminescent earthworm Fridericia heliota.

PubMed

Dubinnyi, Maxim A; Tsarkova, Aleksandra S; Petushkov, Valentin N; Kaskova, Zinaida M; Rodionova, Natalja S; Kovalchuk, Sergey I; Ziganshin, Rustam H; Baranov, Mikhail S; Mineev, Konstantin S; Yampolsky, Ilia V

2015-03-02

We report isolation and structure elucidation of AsLn5, AsLn7, AsLn11 and AsLn12: novel luciferin analogs from the bioluminescent earthworm Fridericia heliota. They were found to be highly unusual modified peptides, comprising either of the two tyrosine-derived chromophores, CompX or CompY and a set of amino acids, including threonine, gamma-aminobutyric acid, homoarginine, and unsymmetrical N,N-dimethylarginine. These natural compounds represent a unique peptide chemistry found in terrestrial animals and rise novel questions concerning their biosynthetic origin. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Animals. Environmental Education Curriculum.

ERIC Educational Resources Information Center

Topeka Public Schools, KS.

The material in this unit is designed to provide upper elementary students with information and experiences to develop a better understanding and appreciation of the variety of animals living today. Unit goals include fostering a better understanding of animals' roles in nature, developing observational skills, facilitating understanding of man's…

From Ends to Causes (and Back Again) by Metaphor: The Paradox of Natural Selection

ERIC Educational Resources Information Center

Blancke, Stefaan; Schellens, Tammy; Soetaert, Ronald; Van Keer, Hilde; Braeckman, Johan

2014-01-01

Natural selection is one of the most famous metaphors in the history of science. Charles Darwin used the metaphor and the underlying analogy to frame his ideas about evolution and its main driving mechanism into a full-fledged theory. Because the metaphor turned out to be such a powerful epistemic tool, Darwin naturally assumed that he could also…

Penetration enhancing effects of selected natural oils utilized in topical dosage forms.

PubMed

Viljoen, Joe M; Cowley, Amé; du Preez, Jan; Gerber, Minja; du Plessis, Jeanetta

2015-01-01

Various natural products, including oils, have been utilized as penetration enhancers due to their "safety profiles". These oils contain fatty acids promoting skin permeability through lipid fluidization within the stratum corneum; and might therefore be able to effectively enhance transdermal drug delivery. We investigated possible penetration enhancing properties of selected oils, utilizing flurbiprofen as marker compound in emulgel formulations. The formulations were compared to a liquid paraffin emulgel and a hydrogel to establish any significant penetration enhancing effects. Gas chromatographic analysis of the natural oils was performed at ambient temperature to determine the fatty acid composition in each selected natural oils. Franz cell diffusion studies and tape stripping methods were employed to study delivery of the marker into, and through the skin. The following rank order for the emulgel flux-values was obtained: Hydrogel > olive oil > liquid paraffin > coconut oil > grape seed oil > Avocado oil ≥ Crocodile oil > Emu oil. Results suggested that oils containing predominantly mono-unsaturated oleic acid, on average increased the flux of the marker to a larger extent than oils containing an almost even mixture of both mono- and poly-unsaturated fatty acids. Oils comprising saturated fatty acids (SFAs) with alkyl chains between C12 and C14, increased the marker flux to a higher extent than oils containing C16-C18 SFAs. Effects observed for branched fatty acids, however, did not vary significantly from effects for unbranched fatty acids with the same carbon chain length. Natural oils possess penetration enhancing effects.

Zoo agent's measure in applying the five freedoms principles for animal welfare.

PubMed

Demartoto, Argyo; Soemanto, Robertus Bellarminus; Zunariyah, Siti

2017-09-01

Animal welfare should be prioritized not only for the animal's life sustainability but also for supporting the sustainability of living organism's life on the earth. However, Indonesian people have not understood it yet, thereby still treating animals arbitrarily and not appreciating either domesticated or wild animals. This research aimed to analyze the zoo agent's action in applying the five freedoms principle for animal welfare in Taman Satwa Taru Jurug (thereafter called TSTJ) or Surakarta Zoo and Gembira Loka Zoo (GLZ) of Yogyakarta Indonesia using Giddens structuration theory. The informants in this comparative study with explorative were organizers, visitors, and stakeholders of zoos selected using purposive sampling technique. The informants consisted of 19 persons: 8 from TSTJ (Code T) and 10 from GLZ (Code G) and representatives from Natural Resource Conservation Center of Central Java (Code B). Data were collected through observation, in-depth interview, and Focus Group Discussion and Documentation. Data were analyzed using an interactive model of analysis consisting of three components: Data reduction, data display, and conclusion drawing. Data validation was carried out using method and data source triangulations. Food, nutrition, and nutrition level have been given consistent with the animals' habit and natural behavior. Animal keepers always maintain their self-cleanliness. GLZ has provided cages according to the technical instruction of constructing ideal cages, but the cages in TSTJ are worrying as they are not consistent with standard, rusty, and damaged, and animals have no partner. Some animals in GLZ are often sick, whereas some animals in TSTJ are dead due to poor maintenance. The iron pillars of cages restrict animal behavior in TSTJ so that they have not had freedom to behave normally yet, whereas, in GLZ, they can move freely in original habitat. The animals in the two zoos have not been free from disruption, stress, and pressure due to the

Measuring Knowledge of Natural Selection: A Comparison of the CINS, an Open-Response Instrument, and an Oral Interview

ERIC Educational Resources Information Center

Nehm, Ross H.; Schonfeld, Irvin Sam

2008-01-01

Growing recognition of the central importance of fostering an in-depth understanding of natural selection has, surprisingly, failed to stimulate work on the development and rigorous evaluation of instruments that measure knowledge of it. We used three different methodological tools, the Conceptual Inventory of Natural Selection (CINS), a modified…

Animating Preservice Teachers' Noticing

ERIC Educational Resources Information Center

de Araujo, Zandra; Amador, Julie; Estapa, Anne; Weston, Tracy; Aming-Attai, Rachael; Kosko, Karl W.

2015-01-01

The incorporation of animation in mathematics teacher education courses is one method for transforming practices and promoting practice-based education. Animation can be used as an approximation of practice that engages preservice teachers (PSTs) in creating classroom scenes in which they select characters, regulate movement, and construct…

Alterations of selected iron management parameters and activity in food-restricted female Wistar rats (animal anorexia models).

PubMed

Wojciak, Rafal W

2014-03-01

The aim of this study was to assess the influence of food-restricted diets (anorexia models) on iron management and activity of rats. 48 rats were divided into 6 groups: 1 control (K) and 5 testing groups (K/2, GI, GII, GIII, GIV). K was fed ad libitum. K/2 received half the portion of the diet of K. The other groups received 100% of the diet eaten by K, but with different models of food restriction: GI-1 day on, 1 day starvation; GII-2 days on, 2 days starvation; GIII-3 days on, 3 days starvation; and GIV-4 days on, 4 days starvation. As a result, all testing groups ate half of the diet consumed by the control group. The concentrations of iron in selected tissues, ferritin, and selected iron management parameters in blood were examined, as well as the animals' activities associated with food craving. The animal anorexia models used in this study had a significant influence on the blood concentrations of hemoglobin (p < 0.01), hematocrit (p < 0.05), RBC (p < 0.05), iron levels in liver (p < 0.05), kidney (p < 0.001), and heart (p < 0.05), the serum ferritin concentration (p < 0.001) and the rats activity (p < 0.001); whereas there was no influence on the other parameters. Generally, the statistically negative effects of starvation models on iron management parameters and activity of animals were observed. However, these effects were dependent on the model of anorexia more than on the quantity of food intake. The negative effect of food deprivation on iron deficiency and rat activities were observed in all groups; however, the strongest effect was noticed in those animals subject to chronic starvation. Acute deprivations caused the reduction of activity in the rats, however, chronic starvation caused an increase in the activity of the first phase of the experiment, followed by a decline in the subsequent phase. It is possible that stress and frustration as well as depression may be caused by insufficient food intake, and as a result, by iron deficiency in a diet

Influences of Teleological and Lamarckian Thinking on Student Understanding of Natural Selection

ERIC Educational Resources Information Center

Stover, Shawn K.; Mabry, Michelle L.

2007-01-01

Previous research has demonstrated creationist, Lamarckian, and teleological reasoning in high school and college students. These lines of thinking conflict with the Darwinian notion of natural selection, which serves as the primary catalyst for biological evolution. The current study assessed evolutionary conceptions in non-science majors,…

Induced responses to competition and herbivory: natural selection on multi-trait phenotypic plasticity.

PubMed

Boege, Karina

2010-09-01

Herbivory and competition are two of the most common biotic stressors for plants. When occurring simultaneously, responses to one interaction can constrain the induction of responses to the other interaction due to resource limitation and other interactive effects. Thus, to maximize fitness when interacting with competitors and herbivores, plants are likely to express particular combinations of plastic responses. This study reports the interactive effects of herbivory and competition on responses induced in Tithonia tubaeformis plants and describes how natural selection acts on particular plastic responses and on their different combinations. Competition induced a stem elongation response, expressed through an increase in height and mean internode length, together with a decrease in basal diameter. Interestingly, realized resistance increased in both competition and herbivory treatments, suggesting a plastic response in both constitutive and induced resistance traits. Particular combinations of plastic responses defined three plant phenotypes: vigorous, elongated, and resistant plants. The ecological context in which plants grew modified the traits and the particular combinations of plastic responses that were favored by selection. Vigorous plants were favored by selection in all environments, except when they were damaged by herbivores in the absence of neighbors. The combination of responses defining an elongated plant phenotype was favored by selection in crowded conditions. Resistance was negatively selected in the absence of competition and herbivory but favored in the presence of both interactions. In addition, contextual analyses detected that population structure in heterogeneous environments can also influence the outcomes of selection. These findings suggest that natural selection can act on particular combinations of plastic responses, which may allow plants to adjust their phenotypes to those that promote greater fitness under particular ecological

Pathological anxiety in animals.

PubMed

Ohl, Frauke; Arndt, Saskia S; van der Staay, F Josef

2008-01-01

Selective breeding programmes in domestic and laboratory animals generally focus on physiological and/or anatomical characteristics. However, selection may have an (unintended) impact on other characteristics and may lead to dysfunctional behaviour that can affect biological functioning and, as a consequence, compromise welfare and quality of life. In this review it is proposed that various behavioural dysfunctions in animals are due to pathological anxiety. Although several approaches have been undertaken to specify the diagnostic criteria of pathological anxiety as a behavioural disorder in animals, the causal aetiology largely remains unknown. This is mainly due to the fact that integrated concepts, combining the behavioural syndrome and (neuro-) physiological processes, are widely lacking. Moreover, even the term anxiety itself represents a poorly defined concept or category. A definition is suggested and the potential causes of pathological anxiety are explored with a plea for developing adequate diagnostic tools and therapies to fight pathological anxiety in animals based on insight from scientific research.

Spatially-Correlated Risk in Nature Reserve Site Selection

PubMed Central

Albers, Heidi J.; Busby, Gwenlyn M.; Hamaide, Bertrand; Ando, Amy W.; Polasky, Stephen

2016-01-01

Establishing nature reserves protects species from land cover conversion and the resulting loss of habitat. Even within a reserve, however, many factors such as fires and defoliating insects still threaten habitat and the survival of species. To address the risk to species survival after reserve establishment, reserve networks can be created that allow some redundancy of species coverage to maximize the expected number of species that survive in the presence of threats. In some regions, however, the threats to species within a reserve may be spatially correlated. As examples, fires, diseases, and pest infestations can spread from a starting point and threaten neighboring parcels’ habitats, in addition to damage caused at the initial location. This paper develops a reserve site selection optimization framework that compares the optimal reserve networks in cases where risks do and do not reflect spatial correlation. By exploring the impact of spatially-correlated risk on reserve networks on a stylized landscape and on an Oregon landscape, this analysis demonstrates an appropriate and feasible method for incorporating such post-reserve establishment risks in the reserve site selection literature as an additional tool to be further developed for future conservation planning. PMID:26789127

The Origin of Mutants Under Selection: How Natural Selection Mimics Mutagenesis (Adaptive Mutation)

PubMed Central

Maisnier-Patin, Sophie; Roth, John R.

2015-01-01

Selection detects mutants but does not cause mutations. Contrary to this dictum, Cairns and Foster plated a leaky lac mutant of Escherichia coli on lactose medium and saw revertant (Lac+) colonies accumulate with time above a nongrowing lawn. This result suggested that bacteria might mutagenize their own genome when growth is blocked. However, this conclusion is suspect in the light of recent evidence that revertant colonies are initiated by preexisting cells with multiple copies the conjugative F′lac plasmid, which carries the lac mutation. Some plated cells have multiple copies of the simple F′lac plasmid. This provides sufficient LacZ activity to support plasmid replication but not cell division. In nongrowing cells, repeated plasmid replication increases the likelihood of a reversion event. Reversion to lac+ triggers exponential cell growth leading to a stable Lac+ revertant colony. In 10% of these plated cells, the high-copy plasmid includes an internal tandem lac duplication, which provides even more LacZ activity—sufficient to support slow growth and formation of an unstable Lac+ colony. Cells with multiple copies of the F′lac plasmid have an increased mutation rate, because the plasmid encodes the error-prone (mutagenic) DNA polymerase, DinB. Without DinB, unstable and stable Lac+ revertant types form in equal numbers and both types arise with no mutagenesis. Amplification and selection are central to behavior of the Cairns–Foster system, whereas mutagenesis is a system-specific side effect or artifact caused by coamplification of dinB with lac. Study of this system has revealed several broadly applicable principles. In all populations, gene duplications are frequent stable genetic polymorphisms, common near-neutral mutant alleles can gain a positive phenotype when amplified under selection, and natural selection can operate without cell division when variability is generated by overreplication of local genome subregions. PMID:26134316

Natural selection drove metabolic specialization of the chromatophore in Paulinella chromatophora.

PubMed

Valadez-Cano, Cecilio; Olivares-Hernández, Roberto; Resendis-Antonio, Osbaldo; DeLuna, Alexander; Delaye, Luis

2017-04-14

Genome degradation of host-restricted mutualistic endosymbionts has been attributed to inactivating mutations and genetic drift while genes coding for host-relevant functions are conserved by purifying selection. Unlike their free-living relatives, the metabolism of mutualistic endosymbionts and endosymbiont-originated organelles is specialized in the production of metabolites which are released to the host. This specialization suggests that natural selection crafted these metabolic adaptations. In this work, we analyzed the evolution of the metabolism of the chromatophore of Paulinella chromatophora by in silico modeling. We asked whether genome reduction is driven by metabolic engineering strategies resulted from the interaction with the host. As its widely known, the loss of enzyme coding genes leads to metabolic network restructuring sometimes improving the production rates. In this case, the production rate of reduced-carbon in the metabolism of the chromatophore. We reconstructed the metabolic networks of the chromatophore of P. chromatophora CCAC 0185 and a close free-living relative, the cyanobacterium Synechococcus sp. WH 5701. We found that the evolution of free-living to host-restricted lifestyle rendered a fragile metabolic network where >80% of genes in the chromatophore are essential for metabolic functionality. Despite the lack of experimental information, the metabolic reconstruction of the chromatophore suggests that the host provides several metabolites to the endosymbiont. By using these metabolites as intracellular conditions, in silico simulations of genome evolution by gene lose recover with 77% accuracy the actual metabolic gene content of the chromatophore. Also, the metabolic model of the chromatophore allowed us to predict by flux balance analysis a maximum rate of reduced-carbon released by the endosymbiont to the host. By inspecting the central metabolism of the chromatophore and the free-living cyanobacteria we found that by

Effects of environmental changes on natural selection active on human polygenic traits.

PubMed

Ulizzi, L

1993-06-01

During the last century, industrialized countries experienced such an improvement in socioeconomic conditions and in sanitation that it is likely that the selective forces active on human metric traits have been modified. Perinatal mortality as a function of birth weight is one of the clearest examples of natural selection in humans. Here, trends over time of stabilizing and directional selection associated with birth weight have been analyzed in Japan from 1969 to 1989. The population of newborns has been subdivided according to gestational age, which is one of the main covariates of birth weight. The results show that in full-term babies both stabilizing and directional selection are coming to an end, whereas in babies born after 8 months of gestation these selective forces are still active, even if at much lower levels than in the past. The peculiar results found in the 7-month-gestation population are probably due to grossly abnormal cases of immaturity.

Learning from Animation Enabled by Collaboration

ERIC Educational Resources Information Center

Rebetez, Cyril; Betrancourt, Mireille; Sangin, Mirweis; Dillenbourg, Pierre

2010-01-01

Animated graphics are extensively used in multimedia instructions explaining how natural or artificial dynamic systems work. As animation directly depicts spatial changes over time, it is legitimate to believe that animated graphics will improve comprehension over static graphics. However, the research failed to find clear evidence in favour of…

Testing natural selection vs. genetic drift in phenotypic evolution using quantitative trait locus data.

PubMed Central

Orr, H A

1998-01-01

Evolutionary biologists have long sought a way to determine whether a phenotypic difference between two taxa was caused by natural selection or random genetic drift. Here I argue that data from quantitative trait locus (QTL) analyses can be used to test the null hypothesis of neutral phenotypic evolution. I propose a sign test that compares the observed number of plus and minus alleles in the "high line" with that expected under neutrality, conditioning on the known phenotypic difference between the taxa. Rejection of the null hypothesis implies a role for directional natural selection. This test is applicable to any character in any organism in which QTL analysis can be performed. PMID:9691061

Notice of release for Eagle Germplasm western yarrow (selected germplasm, natural track)

Treesearch

Scott M. Lambert; Stephen B. Monsen; Nancy Shaw

2011-01-01

The United States Department of Agriculture, Forest Service, Rocky Mountain Research Station; United States Department of the Interior, Bureau of Land Management, Idaho State Office; Utah State University, Agricultural Experiment Station; and University of Idaho, Agricultural Experiment Station, announce the release of a selected germplasm (natural track) of western...

Vocational Agriculture Teachers' Opinions Relative to Selected Animal Science Competencies.

ERIC Educational Resources Information Center

Thomas, Larry G.; Groves, Ramsey

1986-01-01

The attitudes of 107 vocational agriculture teachers toward animal science competencies were compared to those of respondents to the National Agriculture Occupations Competency Study. The areas of disagreement indicate a need for increased cooperation between agricultural education and animal science departments in teacher preparation. (SK)

On the Nature of the First Galaxies Selected at 350 Micrometers

NASA Technical Reports Server (NTRS)

Khan, Sophia A.; Chanial, Pierre F.; Willner, S. P.; Pearson, Chris P.; Ashby, M. L. N.; Benford, Dominic J.; Clements, David L.; Dye, Simon; Farrah, Duncan; Fazio, G. G.;

Animals Underground. Young Discovery Library Series.

ERIC Educational Resources Information Center

Ruffault, Charlotte

This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume explores the natural history of animals that live underground. Animals included are porcupine, insects, earthworm, mole, badger, rabbit, prairie dog, and beach animals. (YP)

What Happens to Animals during Hurricanes? Teachable Moments with Extreme Weather and Animals

ERIC Educational Resources Information Center

Welch, Marti

2006-01-01

Students are concerned about what happens to the animals in the aftermath of natural disasters such as hurricanes, earthquakes, and tsunami. They have remarkable compassion for animals. Students want to know if dolphins, manatees, and sea turtles survive. Furthermore, they want to know what they can do to help. Hence, a variety of teachable…

Natural Selection and Genetic Diversity in the Butterfly Heliconius melpomene.

PubMed

Martin, Simon H; Möst, Markus; Palmer, William J; Salazar, Camilo; McMillan, W Owen; Jiggins, Francis M; Jiggins, Chris D

2016-05-01

A combination of selective and neutral evolutionary forces shape patterns of genetic diversity in nature. Among the insects, most previous analyses of the roles of drift and selection in shaping variation across the genome have focused on the genus Drosophila A more complete understanding of these forces will come from analyzing other taxa that differ in population demography and other aspects of biology. We have analyzed diversity and signatures of selection in the neotropical Heliconius butterflies using resequenced genomes from 58 wild-caught individuals of Heliconius melpomene and another 21 resequenced genomes representing 11 related species. By comparing intraspecific diversity and interspecific divergence, we estimate that 31% of amino acid substitutions between Heliconius species are adaptive. Diversity at putatively neutral sites is negatively correlated with the local density of coding sites as well as nonsynonymous substitutions and positively correlated with recombination rate, indicating widespread linked selection. This process also manifests in significantly reduced diversity on longer chromosomes, consistent with lower recombination rates. Although hitchhiking around beneficial nonsynonymous mutations has significantly shaped genetic variation in H. melpomene, evidence for strong selective sweeps is limited overall. We did however identify two regions where distinct haplotypes have swept in different populations, leading to increased population differentiation. On the whole, our study suggests that positive selection is less pervasive in these butterflies as compared to fruit flies, a fact that curiously results in very similar levels of neutral diversity in these very different insects. Copyright © 2016 by the Genetics Society of America.

Nature of men and higher animals' response to the lunar phases.

NASA Astrophysics Data System (ADS)

Troshichev, Oleg; Vladimir, Vorobeichikov; Viktor, Stepanov; Eduard, Gorshkov

The Moon impact on the abnormal behavior of men and higher animals was marked during the entire mankind history, but the nature of this effect remained unclear. The popular hypothesis of the tidal influence of the Moon on the living organisms turned out to be incompatible with the contemporary biophysics concepts. In addition, the estimates of the lunar gravity influence on the men organism showed the negligible value of the possible effect. Vorobeichikov et al. [2006] were the first who suggested that the organisms' response to the lunar phases can be linked with the bacillus E.coli inhabiting in the bowels of the living organisms. E.coli belongs to family of enterobacteria, which are the important component of the human body microflora. Bacteria E.coli being sowed in the nutritious medium go in their development through four stages: adjusting, explosive reproducing, stationary, and dieing. The adjusting stage (or lagphase) is the most interesting for researchers, since duration of this phase L (the interval between the sowing time and the onset of the quick, exponential reproduction) is strongly influenced by the external conditions and can vary from standard 3 - 3.5 hours to some minutes. In our experiments the lag-phase L was determined for days of new moon and full moon, and for such exclusive events as the solar and lunar eclipses. The standard quantity of E.coli was sowed in the standard volume of the artificial nutritive. Lag-phase was detected every 1 minute near the key moment and every 15 minutes at other hours. It turned out that lag-phase is reduced to 1.5 hour for new moon, 1 hour for full moon, 0.5 hour for the lunar eclipse and falls to zero for the solar eclipse. In the latter case it took about 10 hours for the lag phase reduction before the eclipse and the lag-phase recovery after the eclipse. In case of a new moon the lag phase reduction lasted about half of hour. Thus, the close was the Moon to the line Sun-Earth, the shorter was lag phase and

Implications of quantum metabolism and natural selection for the origin of cancer cells and tumor progression

NASA Astrophysics Data System (ADS)

Davies, Paul; Demetrius, Lloyd A.; Tuszynski, Jack A.

2012-03-01

Empirical studies give increased support for the hypothesis that the sporadic form of cancer is an age-related metabolic disease characterized by: (a) metabolic dysregulation with random abnormalities in mitochondrial DNA, and (b) metabolic alteration - the compensatory upregulation of glycolysis to offset mitochondrial impairments. This paper appeals to the theory of Quantum Metabolism and the principles of natural selection to formulate a conceptual framework for a quantitative analysis of the origin and proliferation of the disease. Quantum Metabolism, an analytical theory of energy transduction in cells inspired by the methodology of the quantum theory of solids, elucidates the molecular basis for differences in metabolic rate between normal cells, utilizing predominantly oxidative phosphorylation, and cancer cells utilizing predominantly glycolysis. The principles of natural selection account for the outcome of competition between the two classes of cells. Quantum Metabolism and the principles of natural selection give an ontogenic and evolutionary rationale for cancer proliferation and furnish a framework for effective therapeutic strategies to impede the spread of the disease.

Beef Cattle: Selection and Evaluation.

ERIC Educational Resources Information Center

Clemson Univ., SC. Vocational Education Media Center.

Designed for secondary vocational agriculture students, this text provides an overview of selecting and evaluating beef cattle in Future Farmers of America livestock judging events. The first of four major sections addresses topics such as the ideal beef animal, selecting steers, selecting breeding animals, studying the animal systematically, and…

Thinking with Crocodiles: An Iconic Animal at the Intersection of Early-Modern Religion and Natural Philosophy.

PubMed

Weinreich, Spencer J

2015-01-01

This paper seeks to explore how culturally and religiously significant animals could shape discourses in which they were deployed, taking the crocodile as its case study. Beginning with the textual and visual traditions linking the crocodile with Africa and the Middle East, I read sixteenth- and seventeenth-century travel narratives categorizing American reptiles as "crocodiles" rather than "alligators," as attempts to mitigate the disruptive strangeness of the Americas. The second section draws on Ann Blair's study of "Mosaic Philosophy" to examine scholarly debates over the taxonomic identity of the biblical Leviathan. I argue that the language and analytical tools of natural philosophy progressively permeated religious discourse. Finally, a survey of more than 25 extant examples of the premodern practice of displaying crocodiles in churches, as well as other crocodilian elements in Christian iconography, provides an explanation for the ubiquity of crocodiles in Wunderkammern, as natural philosophy appropriated ecclesial visual vocabularies.

Injuries due to human and animal aggression in humans.

PubMed

Łabęcka, Marzena; Lorkiewicz-Muszyńska, Dorota E; Przystańska, Agnieszka; Kondrusiewicz, Krzysztof

2013-01-01

People breed animals, professionally take care of them, and work with them. To live with animals, however, it is necessary to know their behaviour and habits, as well as fears. Ignorance of this knowledge may lead to tragedy for the victim (a person), as well as for the beast (animal). Then, nobody cares whether the animal behaved itself or not in accordance with its nature. The aim of the presented study is to compare the rate of animal aggression in relation to cases of documented aggression towards humans. The victims were investigated according to the age, gender and types of injuries caused by animal bites. The protocols of autopsies (2,218) and medical-legal examinations (4,569) performed from 2004-2009 in the Department of Forensic Sciences in Poznań were analyzed. The selected data was studied using Microsoft Office Excel 2007 for Windows. Analysis revealed the presence of animal bite injuries in less than 1% of the deceased victims of aggression. The number of individuals who died as a result of animal bites varied from 1-4 a year, and in all cases these were postmortem injuries. Analysis of injuries among surviving victims of aggression showed animal bite injuries were present in 41 out of 4,569 victims, almost equally among males and females. Moreover, in 25 victims the bite injuries recognized as human were found. The majority of animal bites occurred in adults. The medium injuries were the most frequent in the animal bite victims. Animal aggression is a marginal problem considering all cases of aggression towards humans. In contrast to the aggression of humans towards other humans, this is a very rare cause of human death or even major injury.

Genome-wide detection of natural selection in African Americans pre- and post-admixture

PubMed Central

Jin, Wenfei; Xu, Shuhua; Wang, Haifeng; Yu, Yongguo; Shen, Yiping; Wu, Bailin; Jin, Li

2012-01-01

It is particularly meaningful to investigate natural selection in African Americans (AfA) due to the high mortality their African ancestry has experienced in history. In this study, we examined 491,526 autosomal single nucleotide polymorphisms (SNPs) genotyped in 5210 individuals and conducted a genome-wide search for selection signals in 1890 AfA. Several genomic regions showing an excess of African or European ancestry, which were considered the footprints of selection since population admixture, were detected based on a commonly used approach. However, we also developed a new strategy to detect natural selection both pre- and post-admixture by reconstructing an ancestral African population (AAF) from inferred African components of ancestry in AfA and comparing it with indigenous African populations (IAF). Interestingly, many selection-candidate genes identified by the new approach were associated with AfA-specific high-risk diseases such as prostate cancer and hypertension, suggesting an important role these disease-related genes might have played in adapting to a new environment. CD36 and HBB, whose mutations confer a degree of protection against malaria, were also located in the highly differentiated regions between AAF and IAF. Further analysis showed that the frequencies of alleles protecting against malaria in AAF were lower than those in IAF, which is consistent with the relaxed selection pressure of malaria in the New World. There is no overlap between the top candidate genes detected by the two approaches, indicating the different environmental pressures AfA experienced pre- and post-population admixture. We suggest that the new approach is reasonably powerful and can also be applied to other admixed populations such as Latinos and Uyghurs. PMID:22128132

A rapid method for selecting suitable animal species for studying pathogen interactions with plasma protein ligands in vivo.

PubMed

Naudin, Clément; Schumski, Ariane; Salo-Ahen, Outi M H; Herwald, Heiko; Smeds, Emanuel

2017-05-01

Species tropism constitutes a serious problem for developing relevant animal models of infection. Human pathogens can express virulence factors that show specific selectivity to human proteins, while their affinity for orthologs from other species can vary significantly. Suitable animal species must be used to analyse whether virulence factors are potential targets for drug development. We developed an assay that rapidly predicts applicable animal species for studying virulence factors binding plasma proteins. We used two well-characterized Staphylococcus aureus proteins, SSL7 and Efb, to develop an ELISA-based inhibition assay using plasma from different animal species. The interaction between SSL7 and human C5 and the binding of Efb to human fibrinogen and human C3 was studied. Affinity experiments and Western blot analyses were used to validate the assay. Human, monkey and cat plasma interfered with binding of SSL7 to human C5. Binding of Efb to human fibrinogen was blocked in human, monkey, gerbil and pig plasma, while human, monkey, gerbil, rabbit, cat and guinea pig plasma inhibited the binding of Efb to human C3. These results emphasize the importance of choosing correct animal models, and thus, our approach is a rapid and cost-effective method that can be used to prevent unnecessary animal experiments. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

The Power of Natural Selection: A Guided Investigation of Three Case Studies

ERIC Educational Resources Information Center

Beachly, William

2010-01-01

I describe a quantitative approach to three case studies in evolution that can be used to challenge college freshmen to explore the power of natural selection and ask questions that foster a deeper understanding of its operation and relevance. Hemochromatosis, the peppered moth, and hominid cranial capacity are investigated with a common algebraic…

Using the FAR Guide to Teach Simulations: An Example with Natural Selection

ERIC Educational Resources Information Center

Sickel, Aaron J.; Friedrichsen, Patricia J.

2012-01-01

Engaging students in a predator-prey simulation to teach natural selection is a common activity in secondary biology classrooms. The purpose of this article is to demonstrate how the authors have changed their approach to teaching this activity from a laboratory investigation to a class-constructed simulation. Specifically, the authors drew upon a…

Evidence of Natural Selection Acting on a Polymorphic Hybrid Incompatibility Locus in Mimulus

PubMed Central

Sweigart, Andrea L.; Flagel, Lex E.

2015-01-01

As a common cause of reproductive isolation in diverse taxa, hybrid incompatibilities are fundamentally important to speciation. A key question is which evolutionary forces drive the initial substitutions within species that lead to hybrid dysfunction. Previously, we discovered a simple genetic incompatibility that causes nearly complete male sterility and partial female sterility in hybrids between the two closely related yellow monkeyflower species Mimulus guttatus and M. nasutus. In this report, we fine map the two major incompatibility loci—hybrid male sterility 1 (hms1) and hybrid male sterility 2 (hms2)—to small nuclear genomic regions (each <70 kb) that include strong candidate genes. With this improved genetic resolution, we also investigate the evolutionary dynamics of hms1 in a natural population of M. guttatus known to be polymorphic at this locus. Using classical genetic crosses and population genomics, we show that a 320-kb region containing the hms1 incompatibility allele has risen to intermediate frequency in this population by strong natural selection. This finding provides direct evidence that natural selection within plant species can lead to hybrid dysfunction between species. PMID:25428983

Evidence of natural selection acting on a polymorphic hybrid incompatibility locus in Mimulus.

PubMed

Sweigart, Andrea L; Flagel, Lex E

2015-02-01

As a common cause of reproductive isolation in diverse taxa, hybrid incompatibilities are fundamentally important to speciation. A key question is which evolutionary forces drive the initial substitutions within species that lead to hybrid dysfunction. Previously, we discovered a simple genetic incompatibility that causes nearly complete male sterility and partial female sterility in hybrids between the two closely related yellow monkeyflower species Mimulus guttatus and M. nasutus. In this report, we fine map the two major incompatibility loci-hybrid male sterility 1 (hms1) and hybrid male sterility 2 (hms2)-to small nuclear genomic regions (each <70 kb) that include strong candidate genes. With this improved genetic resolution, we also investigate the evolutionary dynamics of hms1 in a natural population of M. guttatus known to be polymorphic at this locus. Using classical genetic crosses and population genomics, we show that a 320-kb region containing the hms1 incompatibility allele has risen to intermediate frequency in this population by strong natural selection. This finding provides direct evidence that natural selection within plant species can lead to hybrid dysfunction between species. Copyright © 2015 by the Genetics Society of America.

Prevalence of selected bacterial infections associated with the use of animal waste in Louisiana.

PubMed

Hill, Dagne D; Owens, William E; Tchounwou, Paul B

2005-04-01

Human health is a major concern when considering the disposal of large quantities of animal waste. Health concerns could arise from exposure to pathogens and excess nitrogen associated with this form of pollution. The objective was to collect and analyze health data related to selected bacterial infections associated with the use of animal waste in Louisiana. An analysis of adverse health effects has been conducted based on the incidence/prevalence rates of campylobacteriosis, E. coli O157:H7 infection, salmonellosis and shigellosis. The number of reported cases increased during the summer months. Analysis of health data showed that reported disease cases of E. coli O157:H7 were highest among Caucasian infants in the 0-4 year old age category and in Caucasian children in the 5-9 year old age category. Fatalities resulting from salmonellosis are low and increases sharply with age. The number of reported cases of shigellosis was found to be higher in African American males and females than in Caucasians. The high rate of identification in the younger population may result from the prompt seeking of medical care, as well as the frequent ordering of stool examination when symptoms become evident among this group of the population. The association with increasing age and fatality due to salmonellosis could be attributed to declining health and weaker immune systems often found in the older population. It is concluded that both animal waste and non-point source pollution may have a significant impact on human health.

Prevalence of Selected Bacterial Infections Associated with the Use of Animal Waste in Louisiana

PubMed Central

Hill, Dagne D.; Owens, William E.; Tchounwou, Paul B.

2005-01-01

Human health is a major concern when considering the disposal of large quantities of animal waste. Health concerns could arise from exposure to pathogens and excess nitrogen associated with this form of pollution. The objective was to collect and analyze health data related to selected bacterial infections associated with the use of animal waste in Louisiana. An analysis of adverse health effects has been conducted based on the incidence/prevalence rates of campylobacteriosis, E. coli O157:H7 infection, salmonellosis and shigellosis. The number of reported cases increased during the summer months. Analysis of health data showed that reported disease cases of E. coli O157:H7 were highest among Caucasian infants in the 0–4 year old age category and in Caucasian children in the 5–9 year old age category. Fatalities resulting from salmonellosis are low and increases sharply with age. The number of reported cases of shigellosis was found to be higher in African American males and females than in Caucasians. The high rate of identification in the younger population may result from the prompt seeking of medical care, as well as the frequent ordering of stool examination when symptoms become evident among this group of the population. The association with increasing age and fatality due to salmonellosis could be attributed to declining health and weaker immune systems often found in the older population. It is concluded that both animal waste and non-point source pollution may have a significant impact on human health. PMID:16705805

Treatment of a multiple sclerosis animal model by a novel nanodrop formulation of a natural antioxidant

PubMed Central

Binyamin, Orli; Larush, Liraz; Frid, Kati; Keller, Guy; Friedman-Levi, Yael; Ovadia, Haim; Abramsky, Oded; Magdassi, Shlomo; Gabizon, Ruth

2015-01-01

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system and is associated with demyelination, neurodegeneration, and sensitivity to oxidative stress. In this work, we administered a nanodroplet formulation of pomegranate seed oil (PSO), denominated Nano-PSO, to mice induced for experimental autoimmune encephalomyelitis (EAE), an established model of MS. PSO comprises high levels of punicic acid, a unique polyunsaturated fatty acid considered as one of the strongest natural antioxidants. We show here that while EAE-induced mice treated with natural PSO presented some reduction in disease burden, this beneficial effect increased significantly when EAE mice were treated with Nano-PSO of specific size nanodroplets at much lower concentrations of the oil. Pathological examinations revealed that Nano-PSO administration dramatically reduced demyelination and oxidation of lipids in the brains of the affected animals, which are hallmarks of this severe neurological disease. We propose that novel formulations of natural antioxidants such as Nano-PSO may be considered for the treatment of patients suffering from demyelinating diseases. On the mechanistic side, our results demonstrate that lipid oxidation may be a seminal feature in both demyelination and neurodegeneration. PMID:26648720

Transgenic Animals.

ERIC Educational Resources Information Center

Jaenisch, Rudolf

1988-01-01

Describes three methods and their advantages and disadvantages for introducing genes into animals. Discusses the predictability and tissue-specificity of the injected genes. Outlines the applications of transgenic technology for studying gene expression, the early stages of mammalian development, mutations, and the molecular nature of chromosomes.…

Selection of animal models for pre-clinical strategies in evaluating the fracture healing, bone graft substitutes and bone tissue regeneration and engineering.

PubMed

Bigham-Sadegh, Amin; Oryan, Ahmad

2015-06-01

In vitro assays can be useful in determining biological mechanism and optimizing scaffold parameters, however translation of the in vitro results to clinics is generally hard. Animal experimentation is a better approximation than in vitro tests, and usage of animal models is often essential in extrapolating the experimental results and translating the information in a human clinical setting. In addition, usage of animal models to study fracture healing is useful to answer questions related to the most effective method to treat humans. There are several factors that should be considered when selecting an animal model. These include availability of the animal, cost, ease of handling and care, size of the animal, acceptability to society, resistance to surgery, infection and disease, biological properties analogous to humans, bone structure and composition, as well as bone modeling and remodeling characteristics. Animal experiments on bone healing have been conducted on small and large animals, including mice, rats, rabbits, dogs, pigs, goats and sheep. This review also describes the molecular events during various steps of fracture healing and explains different means of fracture healing evaluation including biomechanical, histopathological and radiological assessments.

Active insecticides for Diaphania hyalinata selective for the natural enemy Solenopsis saevissima.

PubMed

Aguiar, Alex R; Alvarenga, Elson S; Lopes, Mayara C; Santos, Izailda B Dos; Galdino, Tarcisio V; Picanço, Marcelo C

2016-09-01

The objective of this study was to determine the toxicity of the nine synthetic dienamides against the insect pest Diaphania hyalinata (melonworm) and the selectivity of these substances for the predator Solenopsis saevissima (fire ant). Four bioassays were conducted. To begin with, the dienamides that caused high mortality of D. hyalinata have been selected. In the second bioassay the dose-mortality curves of the selected dienamides have been constructed. In the third bioassay, the survival curves for D. hyalinata and the elapsed time to kill 50% of their population have been determined. In the fourth biological test, the selectivity of the substances to the predator S. saevissima has been evaluated. The most active (2E,4E)-N-butylhexa-2,4-dienamide 3d has killed 95% of the melonworm, D. hyalinata, and less than 10% of the natural enemy S. saevissima. The results presented by this compound are superior to the outcome displayed by the commercial insecticide Malathion®. Three of the dienamides prepared in this manuscript have proven to be selective in killing the pest, but not the beneficial insect.

Natural Selection and Origin of a Melanistic Allele in North American Gray Wolves.

PubMed

Schweizer, Rena M; Durvasula, Arun; Smith, Joel; Vohr, Samuel H; Stahler, Daniel R; Galaverni, Marco; Thalmann, Olaf; Smith, Douglas W; Randi, Ettore; Ostrander, Elaine A; Green, Richard E; Lohmueller, Kirk E; Novembre, John; Wayne, Robert K

2018-05-01

Pigmentation is often used to understand how natural selection affects genetic variation in wild populations since it can have a simple genetic basis, and can affect a variety of fitness-related traits (e.g., camouflage, thermoregulation, and sexual display). In gray wolves, the K locus, a β-defensin gene, causes black coat color via a dominantly inherited KB allele. The allele is derived from dog-wolf hybridization and is at high frequency in North American wolf populations. We designed a DNA capture array to probe the geographic origin, age, and number of introgression events of the KB allele in a panel of 331 wolves and 20 dogs. We found low diversity in KB, but not ancestral ky, wolf haplotypes consistent with a selective sweep of the black haplotype across North America. Further, North American wolf KB haplotypes are monophyletic, suggesting that a single adaptive introgression from dogs to wolves most likely occurred in the Northwest Territories or Yukon. We use a new analytical approach to date the origin of the KB allele in Yukon wolves to between 1,598 and 7,248 years ago, suggesting that introgression with early Native American dogs was the source. Using population genetic simulations, we show that the K locus is undergoing natural selection in four wolf populations. We find evidence for balancing selection, specifically in Yellowstone wolves, which could be a result of selection for enhanced immunity in response to distemper. With these data, we demonstrate how the spread of an adaptive variant may have occurred across a species' geographic range.

Compensatory selection for roads over natural linear features by wolves in northern Ontario: Implications for caribou conservation

PubMed Central

Patterson, Brent R.; Anderson, Morgan L.; Rodgers, Arthur R.; Vander Vennen, Lucas M.; Fryxell, John M.

2017-01-01

Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism–a compensatory functional response to anthropogenic linear feature

Compensatory selection for roads over natural linear features by wolves in northern Ontario: Implications for caribou conservation.

PubMed

Newton, Erica J; Patterson, Brent R; Anderson, Morgan L; Rodgers, Arthur R; Vander Vennen, Lucas M; Fryxell, John M

2017-01-01

Woodland caribou (Rangifer tarandus caribou) in Ontario are a threatened species that have experienced a substantial retraction of their historic range. Part of their decline has been attributed to increasing densities of anthropogenic linear features such as trails, roads, railways, and hydro lines. These features have been shown to increase the search efficiency and kill rate of wolves. However, it is unclear whether selection for anthropogenic linear features is additive or compensatory to selection for natural (water) linear features which may also be used for travel. We studied the selection of water and anthropogenic linear features by 52 resident wolves (Canis lupus x lycaon) over four years across three study areas in northern Ontario that varied in degrees of forestry activity and human disturbance. We used Euclidean distance-based resource selection functions (mixed-effects logistic regression) at the seasonal range scale with random coefficients for distance to water linear features, primary/secondary roads/railways, and hydro lines, and tertiary roads to estimate the strength of selection for each linear feature and for several habitat types, while accounting for availability of each feature. Next, we investigated the trade-off between selection for anthropogenic and water linear features. Wolves selected both anthropogenic and water linear features; selection for anthropogenic features was stronger than for water during the rendezvous season. Selection for anthropogenic linear features increased with increasing density of these features on the landscape, while selection for natural linear features declined, indicating compensatory selection of anthropogenic linear features. These results have implications for woodland caribou conservation. Prey encounter rates between wolves and caribou seem to be strongly influenced by increasing linear feature densities. This behavioral mechanism-a compensatory functional response to anthropogenic linear feature

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection.

PubMed

Oddie, Melissa A Y; Dahle, Bjørn; Neumann, Peter

2017-01-01

Managed, feral and wild populations of European honey bee subspecies, Apis mellifera , are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor , that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera , is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor , we suggest learning more from nature, i.e., identifying the obviously

Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

PubMed Central

Dahle, Bjørn; Neumann, Peter

2017-01-01

Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Results Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning more from nature, i

Antimicrobial resistance in Escherichia coli isolates from food animals, animal food products and companion animals in China.

PubMed

Lei, Tao; Tian, Wei; He, Liu; Huang, Xian-Hui; Sun, Yong-Xue; Deng, Yu-Ting; Sun, Yan; Lv, Dian-Hong; Wu, Cong-Ming; Huang, Liang-Zong; Shen, Jian-Zhong; Liu, Jian-Hua

2010-11-20

One thousand and thirty Escherichia coli isolates from food animals, animals-derived foods, and companion animals between 2007 and 2008 in Southern China were used to investigate their antimicrobial susceptibility to 14 different antimicrobials by the standard agar dilution method. More than 70% of isolates showed resistance to tetracycline, trimethoprim-sulphamethoxazole, nalidixic acid, and ampicillin. In general, resistance was less frequent in companion animal isolates vs food animals isolates, but cephalosporin and amikacin resistance was more frequent in companion animal isolates, 42.6% to 56.2% vs 14.1% to 24.3%, and 28.5% vs 18.8%, respectively, which was most likely due to the common use of these antimicrobials as treatment in pet animals. Fluoroquinolones resistance was high in all animal isolates (>50%). Food products showed lowest resistance among isolates from these three resources. PFGE analysis indicated that a majority of multidrug-resistant E. coli isolates showed unique, unrelated PFGE profiles and were unlikely to be the spread of a specific clone. This study provides useful information about the prevalence of antimicrobial resistance in E. coli isolated from animals and food products in China and provided evidence of the linkage of the use of antimicrobials in animals and its selection of antimicrobial resistance in bacterial isolates. The data from this study further warns the prudent use of antimicrobials in food and pet animals to reduce the risks of transmission of antimicrobial resistance zoonotic pathogen to humans. Copyright © 2010 Elsevier B.V. All rights reserved.

Selective Removal of Natural Occlusal Caries by Coupling Near-infrared Imaging with a CO2 Laser

PubMed Central

Tao, You-Chen; Fried, Daniel

2011-01-01

Laser removal of dental hard tissue can be combined with optical, spectral or acoustic feedback systems to selectively ablate dental caries and restorative materials. Near-infrared (NIR) imaging has considerable potential for the optical discrimination of sound and demineralized tissue. Last year we successfully demonstrated that near-IR images can be used to guide a CO2 laser ablation system for the selective removal of artificial caries lesions on smooth surfaces. The objective of this study was to test the hypothesis that two-dimensional near-infrared images of natural occlusal caries can be used to guide a CO2 laser for selective removal. Two-dimensional NIR images were acquired at 1310-nm of extracted human molar teeth with occlusal caries. Polarization sensitive optical coherence tomography (PS-OCT) was also used to acquire depth-resolved images of the lesion areas. An imaging processing module was developed to analyze the NIR imaging output and generate optical maps that were used to guide a CO2 laser to selectively remove the lesions at a uniform depth. Post-ablation NIR images were acquired to verify caries removal. Based on the analysis of the NIR images, caries lesions were selectively removed with a CO2 laser while sound tissues were conserved. However, the removal rate varied markedly with the severity of decay and multiple passes were required for caries removal. These initial results are promising but indicate that the selective removal of natural caries is more challenging than the selective removal of artificial lesions due to varying tooth geometry, the highly variable organic/mineral ratio in natural lesions and more complicated lesion structure. PMID:21909225

Selective removal of natural occlusal caries by coupling near-infrared imaging with a CO II laser

NASA Astrophysics Data System (ADS)

Tao, You-Chen; Fried, Daniel

2008-02-01

Laser removal of dental hard tissue can be combined with optical, spectral or acoustic feedback systems to selectively ablate dental caries and restorative materials. Near-infrared (NIR) imaging has considerable potential for the optical discrimination of sound and demineralized tissue. Last year we successfully demonstrated that near-IR images can be used to guide a CO2 laser ablation system for the selective removal of artificial caries lesions on smooth surfaces. The objective of this study was to test the hypothesis that two-dimensional near-infrared images of natural occlusal caries can be used to guide a CO2 laser for selective removal. Two-dimensional NIR images were acquired at 1310-nm of extracted human molar teeth with occlusal caries. Polarization sensitive optical coherence tomography (PS-OCT) was also used to acquire depth-resolved images of the lesion areas. An imaging processing module was developed to analyze the NIR imaging output and generate optical maps that were used to guide a CO2 laser to selectively remove the lesions at a uniform depth. Post-ablation NIR images were acquired to verify caries removal. Based on the analysis of the NIR images, caries lesions were selectively removed with a CO2 laser while sound tissues were conserved. However, the removal rate varied markedly with the severity of decay and multiple passes were required for caries removal. These initial results are promising but indicate that the selective removal of natural caries is more challenging than the selective removal of artificial lesions due to varying tooth geometry, the highly variable organic/mineral ratio in natural lesions and more complicated lesion structure.

Selective Removal of Natural Occlusal Caries by Coupling Near-infrared Imaging with a CO(2) Laser.

PubMed

Tao, You-Chen; Fried, Daniel

2008-03-01

Laser removal of dental hard tissue can be combined with optical, spectral or acoustic feedback systems to selectively ablate dental caries and restorative materials. Near-infrared (NIR) imaging has considerable potential for the optical discrimination of sound and demineralized tissue. Last year we successfully demonstrated that near-IR images can be used to guide a CO(2) laser ablation system for the selective removal of artificial caries lesions on smooth surfaces. The objective of this study was to test the hypothesis that two-dimensional near-infrared images of natural occlusal caries can be used to guide a CO(2) laser for selective removal. Two-dimensional NIR images were acquired at 1310-nm of extracted human molar teeth with occlusal caries. Polarization sensitive optical coherence tomography (PS-OCT) was also used to acquire depth-resolved images of the lesion areas. An imaging processing module was developed to analyze the NIR imaging output and generate optical maps that were used to guide a CO(2) laser to selectively remove the lesions at a uniform depth. Post-ablation NIR images were acquired to verify caries removal. Based on the analysis of the NIR images, caries lesions were selectively removed with a CO(2) laser while sound tissues were conserved. However, the removal rate varied markedly with the severity of decay and multiple passes were required for caries removal. These initial results are promising but indicate that the selective removal of natural caries is more challenging than the selective removal of artificial lesions due to varying tooth geometry, the highly variable organic/mineral ratio in natural lesions and more complicated lesion structure.

Interspecies differences in the empty body chemical composition of domestic animals.

PubMed

Maeno, H; Oishi, K; Hirooka, H

2013-07-01

Domestication of animals has resulted in phenotypic changes by means of natural and human-directed selection. Body composition is important for farm animals because it reflects the status of energy reserves. Thus, there is the possibility that farm animals as providers of food have been more affected by human-directed selection for body composition than laboratory animals. In this study, an analysis was conducted to determine what similarities and differences in body composition occur between farm and laboratory animals using literature data obtained from seven comparative slaughter studies (n = 136 observations). Farm animals from four species (cattle, goats, pigs and sheep) were all castrated males, whereas laboratory animals from three species (dogs, mice and rats) comprised males and/or females. All animals were fed ad libitum. The allometric equation, Y = aX b , was used to determine the influence of species on the accretion rates of chemical components (Y, kg) relative to the growth of the empty body, fat-free empty body or protein weights (X, kg). There were differences between farm and laboratory animals in terms of the allometric growth coefficients for chemical components relative to the empty BW and fat-free empty BW (P < 0.01); farm animals had more rapid accretion rates of fat (P < 0.01) but laboratory animals had more rapid accretion rates of protein, water and ash (P < 0.01). In contrast, there was no difference in terms of the allometric growth coefficients for protein and water within farm animals (P > 0.2). The allometric growth coefficients for ash weight relative to protein weight for six species except sheep were not different from a value of 1 (P > 0.1), whereas that of sheep was smaller than 1 (P < 0.01). When compared at the same fat content of the empty body, the rate of change in water content (%) per unit change in fat content (%) was not different (P > 0.05) across farm animal species and similar ash-to-protein ratios were obtained

Sexual and natural selection in the evolution of extended phenotypes: the use of green nesting material in starlings.

PubMed

Rubalcaba, J G; Polo, V; Maia, R; Rubenstein, D R; Veiga, J P

2016-08-01

Although sexual selection is typically considered the predominant force driving the evolution of ritualized sexual behaviours, natural selection may also play an important and often underappreciated role. The use of green aromatic plants among nesting birds has been interpreted as a component of extended phenotype that evolved either via natural selection due to potential sanitary functions or via sexual selection as a signal of male attractiveness. Here, we compared both hypotheses using comparative methods in starlings, a group where this behaviour is widespread. We found that the use of green plants was positively related to male-biased size dimorphism and that it was most likely to occur among cavity-nesting species. These results suggest that this behaviour is likely favoured by sexual selection, but also related to its sanitary use in response to higher parasite loads in cavities. We speculate that the use of green plants in starlings may be facilitated by cavity nesting and was subsequently co-opted as a sexual signal by males. Our results represent an example of how an extended phenotypic component of males becomes sexually selected by females. Thus, both natural selection and sexual selection are necessary to fully understand the evolution of ritualized behaviours involved in courtship. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Incipient balancing selection through adaptive loss of aquaporins in natural Saccharomyces cerevisiae populations.

PubMed

Will, Jessica L; Kim, Hyun Seok; Clarke, Jessica; Painter, John C; Fay, Justin C; Gasch, Audrey P

2010-04-01

A major goal in evolutionary biology is to understand how adaptive evolution has influenced natural variation, but identifying loci subject to positive selection has been a challenge. Here we present the adaptive loss of a pair of paralogous genes in specific Saccharomyces cerevisiae subpopulations. We mapped natural variation in freeze-thaw tolerance to two water transporters, AQY1 and AQY2, previously implicated in freeze-thaw survival. However, whereas freeze-thaw-tolerant strains harbor functional aquaporin genes, the set of sensitive strains lost aquaporin function at least 6 independent times. Several genomic signatures at AQY1 and/or AQY2 reveal low variation surrounding these loci within strains of the same haplotype, but high variation between strain groups. This is consistent with recent adaptive loss of aquaporins in subgroups of strains, leading to incipient balancing selection. We show that, although aquaporins are critical for surviving freeze-thaw stress, loss of both genes provides a major fitness advantage on high-sugar substrates common to many strains' natural niche. Strikingly, strains with non-functional alleles have also lost the ancestral requirement for aquaporins during spore formation. Thus, the antagonistic effect of aquaporin function-providing an advantage in freeze-thaw tolerance but a fitness defect for growth in high-sugar environments-contributes to the maintenance of both functional and nonfunctional alleles in S. cerevisiae. This work also shows that gene loss through multiple missense and nonsense mutations, hallmarks of pseudogenization presumed to emerge after loss of constraint, can arise through positive selection.

Incipient Balancing Selection through Adaptive Loss of Aquaporins in Natural Saccharomyces cerevisiae Populations

PubMed Central

Will, Jessica L.; Kim, Hyun Seok; Clarke, Jessica; Painter, John C.; Fay, Justin C.; Gasch, Audrey P.

2010-01-01

A major goal in evolutionary biology is to understand how adaptive evolution has influenced natural variation, but identifying loci subject to positive selection has been a challenge. Here we present the adaptive loss of a pair of paralogous genes in specific Saccharomyces cerevisiae subpopulations. We mapped natural variation in freeze-thaw tolerance to two water transporters, AQY1 and AQY2, previously implicated in freeze-thaw survival. However, whereas freeze-thaw–tolerant strains harbor functional aquaporin genes, the set of sensitive strains lost aquaporin function at least 6 independent times. Several genomic signatures at AQY1 and/or AQY2 reveal low variation surrounding these loci within strains of the same haplotype, but high variation between strain groups. This is consistent with recent adaptive loss of aquaporins in subgroups of strains, leading to incipient balancing selection. We show that, although aquaporins are critical for surviving freeze-thaw stress, loss of both genes provides a major fitness advantage on high-sugar substrates common to many strains' natural niche. Strikingly, strains with non-functional alleles have also lost the ancestral requirement for aquaporins during spore formation. Thus, the antagonistic effect of aquaporin function—providing an advantage in freeze-thaw tolerance but a fitness defect for growth in high-sugar environments—contributes to the maintenance of both functional and nonfunctional alleles in S. cerevisiae. This work also shows that gene loss through multiple missense and nonsense mutations, hallmarks of pseudogenization presumed to emerge after loss of constraint, can arise through positive selection. PMID:20369021

Dose imprecision and resistance: free-choice medicated feeds in industrial food animal production in the United States.

PubMed

Love, David C; Davis, Meghan F; Bassett, Anna; Gunther, Andrew; Nachman, Keeve E

2011-03-01

Industrial food animal production employs many of the same antibiotics or classes of antibiotics that are used in human medicine. These drugs can be administered to food animals in the form of free-choice medicated feeds (FCMF), where animals choose how much feed to consume. Routine administration of these drugs to livestock selects for microorganisms that are resistant to medications critical to the treatment of clinical infections in humans. In this commentary, we discuss the history of medicated feeds, the nature of FCMF use with regard to dose delivery, and U.S. policies that address antimicrobial drug use in food animals. FCMF makes delivering a predictable, accurate, and intended dose difficult. Overdosing can lead to animal toxicity; underdosing or inconsistent dosing can result in a failure to resolve animal diseases and in the development of antimicrobial-resistant microorganisms. The delivery of antibiotics to food animals for reasons other than the treatment of clinically diagnosed disease, especially via free-choice feeding methods, should be reconsidered.

Uniting Statistical and Individual-Based Approaches for Animal Movement Modelling

PubMed Central

Latombe, Guillaume; Parrott, Lael; Basille, Mathieu; Fortin, Daniel

2014-01-01

The dynamic nature of their internal states and the environment directly shape animals' spatial behaviours and give rise to emergent properties at broader scales in natural systems. However, integrating these dynamic features into habitat selection studies remains challenging, due to practically impossible field work to access internal states and the inability of current statistical models to produce dynamic outputs. To address these issues, we developed a robust method, which combines statistical and individual-based modelling. Using a statistical technique for forward modelling of the IBM has the advantage of being faster for parameterization than a pure inverse modelling technique and allows for robust selection of parameters. Using GPS locations from caribou monitored in Québec, caribou movements were modelled based on generative mechanisms accounting for dynamic variables at a low level of emergence. These variables were accessed by replicating real individuals' movements in parallel sub-models, and movement parameters were then empirically parameterized using Step Selection Functions. The final IBM model was validated using both k-fold cross-validation and emergent patterns validation and was tested for two different scenarios, with varying hardwood encroachment. Our results highlighted a functional response in habitat selection, which suggests that our method was able to capture the complexity of the natural system, and adequately provided projections on future possible states of the system in response to different management plans. This is especially relevant for testing the long-term impact of scenarios corresponding to environmental configurations that have yet to be observed in real systems. PMID:24979047

Uniting statistical and individual-based approaches for animal movement modelling.

PubMed

Latombe, Guillaume; Parrott, Lael; Basille, Mathieu; Fortin, Daniel

2014-01-01

The dynamic nature of their internal states and the environment directly shape animals' spatial behaviours and give rise to emergent properties at broader scales in natural systems. However, integrating these dynamic features into habitat selection studies remains challenging, due to practically impossible field work to access internal states and the inability of current statistical models to produce dynamic outputs. To address these issues, we developed a robust method, which combines statistical and individual-based modelling. Using a statistical technique for forward modelling of the IBM has the advantage of being faster for parameterization than a pure inverse modelling technique and allows for robust selection of parameters. Using GPS locations from caribou monitored in Québec, caribou movements were modelled based on generative mechanisms accounting for dynamic variables at a low level of emergence. These variables were accessed by replicating real individuals' movements in parallel sub-models, and movement parameters were then empirically parameterized using Step Selection Functions. The final IBM model was validated using both k-fold cross-validation and emergent patterns validation and was tested for two different scenarios, with varying hardwood encroachment. Our results highlighted a functional response in habitat selection, which suggests that our method was able to capture the complexity of the natural system, and adequately provided projections on future possible states of the system in response to different management plans. This is especially relevant for testing the long-term impact of scenarios corresponding to environmental configurations that have yet to be observed in real systems.

Enhancing human-animal relationships through veterinary medical instruction in animal-assisted therapy and animal-assisted activities.

PubMed

Schaffer, Caroline Brunsman

2008-01-01

Instruction in animal-assisted therapy (AAT) and animal-assisted activities (AAAs) teaches veterinary medical students to confidently and assertively maximize the benefits and minimize the risks of this union of animals and people. Instruction in AAT/AAA also addresses requirements by the American Veterinary Medical Association Council on Education that accredited schools/colleges of veterinary medicine include in their standard curriculum the topics of the human-animal bond, behavior, and the contributions of the veterinarian to the overall public and professional health care teams. Entry-level veterinarians should be prepared to: (1) assure that animals who provide AAT/AAA are healthy enough to visit nursing homes, hospitals, or other institutions; (2) promote behavior testing that selects animals who will feel safe, comfortable, and connected; (3) advise facilities regarding infection control and ways to provide a safe environment where the animals, their handlers, and the people being visited will not be injured or become ill; and (4) advocate for their patients and show compassion for their clients when animals are determined to be inappropriate participants in AAT/AAA programs. This article presents AAT/AAA terminology, ways in which veterinarians can advocate for AAT/AAA, the advantages of being involved in AAT/AAA, a model AAT/AAA practicum from Tuskegee University's School of Veterinary Medicine (TUSVM), and examples of co-curricular activities in AAT/AAA by TUSVM's student volunteers.

Homophyly/kinship hypothesis: Natural communities, and predicting in networks

NASA Astrophysics Data System (ADS)

Li, Angsheng; Li, Jiankou; Pan, Yicheng

2015-02-01

It has been a longstanding challenge to understand natural communities in real world networks. We proposed a community finding algorithm based on fitness of networks, two algorithms for prediction, accurate prediction and confirmation of keywords for papers in the citation network Arxiv HEP-TH (high energy physics theory), and the measures of internal centrality, external de-centrality, internal and external slopes to characterize the structures of communities. We implemented our algorithms on 2 citation and 5 cooperation graphs. Our experiments explored and validated a homophyly/kinship principle of real world networks. The homophyly/kinship principle includes: (1) homophyly is the natural selection in real world networks, similar to Darwin's kinship selection in nature, (2) real world networks consist of natural communities generated by the natural selection of homophyly, (3) most individuals in a natural community share a short list of common attributes, (4) natural communities have an internal centrality (or internal heterogeneity) that a natural community has a few nodes dominating most of the individuals in the community, (5) natural communities have an external de-centrality (or external homogeneity) that external links of a natural community homogeneously distributed in different communities, and (6) natural communities of a given network have typical structures determined by the internal slopes, and have typical patterns of outgoing links determined by external slopes, etc. Our homophyly/kinship principle perfectly matches Darwin's observation that animals from ants to people form social groups in which most individuals work for the common good, and that kinship could encourage altruistic behavior. Our homophyly/kinship principle is the network version of Darwinian theory, and builds a bridge between Darwinian evolution and network science.

The Right "Fit": Exploring Science Teacher Candidates' Approaches to Natural Selection Within a Clinical Simulation

NASA Astrophysics Data System (ADS)

Dotger, Benjamin; Dotger, Sharon; Masingila, Joanna; Rozelle, Jeffrey; Bearkland, Mary; Binnert, Ashley

2018-06-01

Teachers and students struggle with the complexities surrounding the evolution of species and the process of natural selection. This article examines how science teacher candidates (STCs) engage in a clinical simulation that foregrounds two common challenges associated with natural selection—students' understanding of "survival of the fittest" and the variation of species over time. We outline the medical education pedagogy of clinical simulations and its recent diffusion to teacher education. Then, we outline the study that situates each STC in a one-to-one interaction with a standardized student who is struggling to accurately interpret natural selection concepts. In simulation with the standardized student, each STC is challenged to recognize content misconceptions and respond with appropriate instructional strategies and accurate explanations. Findings and implications center on the STCs' instructional practices in the simulation and the use of clinical learning environments to foster science teacher learning.

The Right "Fit": Exploring Science Teacher Candidates' Approaches to Natural Selection Within a Clinical Simulation

NASA Astrophysics Data System (ADS)

Dotger, Benjamin; Dotger, Sharon; Masingila, Joanna; Rozelle, Jeffrey; Bearkland, Mary; Binnert, Ashley

2017-04-01

Teachers and students struggle with the complexities surrounding the evolution of species and the process of natural selection. This article examines how science teacher candidates (STCs) engage in a clinical simulation that foregrounds two common challenges associated with natural selection—students' understanding of "survival of the fittest" and the variation of species over time. We outline the medical education pedagogy of clinical simulations and its recent diffusion to teacher education. Then, we outline the study that situates each STC in a one-to-one interaction with a standardized student who is struggling to accurately interpret natural selection concepts. In simulation with the standardized student, each STC is challenged to recognize content misconceptions and respond with appropriate instructional strategies and accurate explanations. Findings and implications center on the STCs' instructional practices in the simulation and the use of clinical learning environments to foster science teacher learning.

A rational design for the nanoencapsulation of poisonous animal venoms in liposomes prepared with natural phospholipids.

PubMed

da Costa, Maria Helena Bueno; Sant'Anna, Osvaldo A; Quintilio, Wagner; Schwendener, Reto Albert; de Araujo, Pedro Soares

2012-11-01

Liposomes have been used since the 1970's to encapsulate drugs envisaging enhancement in efficacy and therapeutic index, avoidance of side effects and increase in the encapsulated agent stability. The major problem when encapsulating snake venoms is the liposomal membrane instability caused by venom phospholipases. Here the results obtained encapsulating Crotalus durissimus terrificus and a pool of Bothropic venoms within liposomes (LC and LB, respectively) used to produce anti-venom sera are presented. The strategy was to modify the immunization protocol to enhance antibody production and to minimize toxic effects by encapsulating inactivated venoms within stabilized liposomes. Chemically modified venoms were solubilized in a buffer containing an inhibitor and a chelating agent. The structures of the venoms were analyzed by UV, CD spectroscopy and ELISA. In spite of the differences in the helical content between natural and modified venoms, they were recognized by horse anti-sera. To maintain long-term stability, mannitol was used as a cryoprotectant. The encapsulation efficiencies were 59 % (LB) and 99 % (LC), as followed by filtration on Sephacryl S1000. Light scattering measurements led us to conclude that both, LB (119 ±47 nm) and LC (147±56 nm) were stable for 22 days at 4 °C, even after lyophilization. Genetically selected mice and mixed breed horses were immunized with these formulations. The animals did not show clinical symptoms of venom toxicity. Both, LB and LC enhanced by at least 30 % the antibody titers 25 days after injection and total IgG titers remained high 91 days after immunization. The liposomal formulation clearly exhibited adjuvant properties.

[Morpho-functional reaction of spleen natural killer cells and macrophages to melatonin administration to the animals kept on different illumination regimens].

PubMed

Shatskikh, O A; Luzikova, E M

2012-01-01

The aim this investigation was to study the changes in the numbers of spleen CD57+ and CD68+ cells (natural killer cells and macrophages respectively) after melatonin administration to the animals kept on different illumination regimens. The experimental animals were given melatonin in dose of 0.03 mg per day for 2 and 4 weeks under conditions of natural illumination or artificial darkening. Spleen paraffin sections were stained using immunohistochemical methods for detection of CD57+ and CD68+ cells. It was shown that long-term administration of melatonin under conditions of natural illumination had an immunosuppressive effect, that was manifested by the depopulation of the marginal zones, white pulp and all the zones of the red pulp, parenchyma loosening and denudation of the reticular stroma of the organ. However, long-term hormone administration under conditions of artificial darkening had an immunostimulatory effect as evidenced by the increased inflow of immunocompetent cells into the spleen, their migration from the white pulp into the marginal zones and emigration into peripheral blood flow, concomitant with the increase in the number of lymphoid nodules. The number of CD57+ and CD68+ cells was increased in splenic periarterial lymphoid sheaths and decreased in B-dependent zones of the organ.

In Darwinian evolution, feedback from natural selection leads to biased mutations.

PubMed

Caporale, Lynn Helena; Doyle, John

2013-12-01

Natural selection provides feedback through which information about the environment and its recurring challenges is captured, inherited, and accumulated within genomes in the form of variations that contribute to survival. The variation upon which natural selection acts is generally described as "random." Yet evidence has been mounting for decades, from such phenomena as mutation hotspots, horizontal gene transfer, and highly mutable repetitive sequences, that variation is far from the simplifying idealization of random processes as white (uniform in space and time and independent of the environment or context).  This paper focuses on what is known about the generation and control of mutational variation, emphasizing that it is not uniform across the genome or in time, not unstructured with respect to survival, and is neither memoryless nor independent of the (also far from white) environment. We suggest that, as opposed to frequentist methods, Bayesian analysis could capture the evolution of nonuniform probabilities of distinct classes of mutation, and argue not only that the locations, styles, and timing of real mutations are not correctly modeled as generated by a white noise random process, but that such a process would be inconsistent with evolutionary theory. © 2013 New York Academy of Sciences.