scholarly journals Model and Data Concur and Explain the Coexistence of Two Very Distinct Animal Behavioral Types

Biology ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 241
Author(s):  
Jordi Moya-Laraño ◽  
Rubén Rabaneda-Bueno ◽  
Emily Morrison ◽  
Philip Crowley

Behaviors may enhance fitness in some situations while being detrimental in others. Linked behaviors (behavioral syndromes) may be central to understanding the maintenance of behavioral variability in natural populations. The spillover hypothesis of premating sexual cannibalism by females explains genetically determined female aggression towards both prey and males: growth to a larger size translates into higher fecundity, but at the risk of insufficient sperm acquisition. Here, we use an individual-based model to determine the ecological scenarios under which this spillover strategy is more likely to evolve over a strategy in which females attack approaching males only once the female has previously secured sperm. We found that a classic spillover strategy could never prevail. However, a more realistic early-spillover strategy, in which females become adults earlier in addition to reaching a larger size, could be maintained in some ecological scenarios and even invade a population of females following the other strategy. We also found under some ecological scenarios that both behavioral types coexist through frequency-dependent selection. Additionally, using data from the spider Lycosa hispanica, we provide strong support for the prediction that the two strategies may coexist in the wild. Our results clarify how animal personalities evolve and are maintained in nature.

2017 ◽  
Author(s):  
Maurine Neiman ◽  
Patrick G. Meirmans ◽  
Tanja Schwander ◽  
Stephanie Meirmans

AbstractWhy and how sexual reproduction is maintained in natural populations, the so-called “queen of problems”, is a key unanswered question in evolutionary biology. Recent efforts to solve the problem of sex have often emphasized results generated from laboratory settings. Here, we use a survey of representative “sex in the wild” literature to review and synthesize the outcomes of empirical studies focused on natural populations. Especially notable results included relatively strong support for mechanisms involving niche differentiation and a near absence of attention to adaptive evolution. Support for a major role of parasites is largely confined to a single study system, and only three systems contribute most of the support for mutation accumulation hypotheses. This evidence for taxon specificity suggests that outcomes of particular studies should not be more broadly extrapolated without extreme caution. We conclude by suggesting steps forward, highlighting tests of niche differentiation mechanisms in both lab and nature and empirical evaluation of adaptive evolution-focused hypotheses in the wild. We also emphasize the value of leveraging the growing body of genomic resources for non-model taxa to address whether the clearance of harmful mutations and spread of beneficial variants in natural populations proceeds as expected under various hypotheses for sex.Author contributionsSM and MN conceived the paper idea, SM, PM, MN, and TS designed the review strategy, reviewed and analysed the literature, and wrote the manuscript. All authors gave final approval for publication.Data archival locationThe results of our literature survey are provided as electronic supplementary material.


1995 ◽  
Vol 31 (10) ◽  
pp. 29-40 ◽  
Author(s):  
J. E. Thorpe ◽  
C. Young Cho

Most species in aquaculture are new to cultivation and so behave like wild animals. They are products of evolution, with adaptations to specific habitat conditions. In the wild, food is not available uniformly throughout the day or the year, or in space, and rarely exceeds the fishes needs. Competition is energetically expensive, reducing growth efficiency. Consequently, feeding activity patterns have evolved, implying internal appetite rhythms, which optimise food intake under these various constraints. Salmonids can adapt quickly to short term variation in food availability, but show seasonal genetically determined anorexia. Rational feeding regimes in culture should take all such features into account. When appetite is high naturally, food should be presented so that it is economically indefensible - where every individual can eat, and where fighting does not pay. At periods of anorexia it will be prudent to offer no food. Manufacturers' feed tables are usually regimes devised to meet the bioenergetic needs of fishes, as they are understood in a physico-chemical sense. While useful first approximations, they do not take into account these evolutionary features of the fishes, and can lead to waste. Methods of presentation are described which allow the fish to determine when food shall be available, and in ways which, by diminishing the advantages of social dominance, ensure relatively even opportunities to feed for all individuals in the population. Allowing the fish to set the time-table reduces the likelihood of waste.


Author(s):  
Carl N. Keiser ◽  
James L.L. Lichtenstein ◽  
Colin M. Wright ◽  
Gregory T. Chism ◽  
Jonathan N. Pruitt

The field of animal behavior has experienced a surge of studies focusing on functional differences among individuals in their behavioral tendencies (‘animal personalities’) and the relationships between different axes of behavioral variation (‘behavioral syndromes’). Many important developments in this field have arisen through research using insects and other terrestrial arthropods, in part, because they present the opportunity to test hypotheses not accessible in other taxa. This chapter reviews how studies on insects and spiders have advanced the study of animal personalities by describing the mechanisms underlying the emergence of individual variation and their ecological consequences. Furthermore, studies accounting for animal personalities can expand our understanding of phenomena in insect science like metamorphosis, eusociality, and applied insect behavior. In addition, this chapter serves to highlight some of the most exciting issues at the forefront of our field and to inspire entomologists and behaviorists alike to seek the answers to these questions.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bert Thys ◽  
Andrea S. Grunst ◽  
Nicky Staes ◽  
Rianne Pinxten ◽  
Marcel Eens ◽  
...  

AbstractQuantifying variation in behaviour-related genes provides insight into the evolutionary potential of repeatable among-individual variation in behaviour (i.e. personality). Yet, individuals typically also plastically adjust their behaviour in response to environmental conditions and/or age, thereby complicating the detection of genotype–phenotype associations. Here, using a population of free-living great tits (Parus major), we assessed the association between single nucleotide polymorphisms (SNPs) in the serotonin transporter gene (SERT) and two repeatable behavioural traits, i.e. female-female aggression and female hissing behaviour. For female-female aggression, a trait showing age-related plasticity, we found no evidence for associations with SERT SNPs, even when assessing potential age-dependent effects of SERT genotype on aggression. We also found no strong support for associations between SERT SNPs and hissing behaviour, yet we identified two synonymous polymorphisms (exon 13 SNP66 and exon 12 SNP144) of particular interest, each explaining about 1.3% of the total variation in hissing behaviour. Overall, our results contribute to the general understanding of the biological underpinning of complex behavioural traits and will facilitate further (meta-analytic) research on behaviour-related genes. Moreover, we emphasize that future molecular genetic studies should consider age-dependent genotype–phenotype associations for behavioural trait (co)variation, as this will vastly improve our understanding of the proximate causes and ultimate consequences of personality variation in natural populations.


2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.


Genetics ◽  
1978 ◽  
Vol 88 (2) ◽  
pp. 367-390
Author(s):  
Ranajit Chakraborty ◽  
Paul A Fuerst ◽  
Masatoshi Nei

ABSTRACT With the aim of testing the validity of the mutation-drift hypothesis, we examined the pattern of genetic differentiation between populations by using data from Drosophila, fishes, reptiles, and mammals. The observed relationship between genetic identity and correlation of heterozygosities of different populations or species was generally in good agreement with the theoretical expectations from the mutation-drift theory, when the variation in mutation rate among loci was taken into account. In some species of Drosophila, however, the correlation was unduly high. The relationship between the mean and variance of genetic distance was also in good agreement with the theoretical prediction in almost all organisms. We noted that both the distribution of heterozygosity within species and the pattern of genetic differentiation between species can be explained by the same set of genetic parameters in each group of organisms. Alternative hypotheses for explaining these observations are discussed.


2020 ◽  
Author(s):  
Martin Reichard ◽  
Radim Blažek ◽  
Jakub Žák ◽  
Petr Kačer ◽  
Oldřich Tomášek ◽  
...  

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.


Genetics ◽  
1978 ◽  
Vol 88 (4) ◽  
pp. 755-759
Author(s):  
Annie Fleuriet

ABSTRACT Polymorphism for both alleles of a gene ref(2)P, which is a usual trait of French natural populations of Drosophila melanogaster, can be reproduced in experimental conditions. ref(2)P is a gene for resistance to the hereditary, noncontagious Rhabdovirus α, responsible for CO2 sensitivity in Drosophila melanogaster. The equilibrium frequencies observed in cages are the same as in the wild, whether α virus is present or not. The rapid rate of return to these equilibrium frequencies indicates that strong forces, which remain to be determined, are responsible for the maintenance of this polymorphism.


2006 ◽  
Vol 28 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Kenneth J. Klassen ◽  
Richard C. Sansing

This paper develops a model of dynamic tax planning in which the implementation of a tax plan involves exercising an option to execute an irreversible investment or financing structure transaction. The model considers four aspects of such transactions and shows that transactions are deferred if the tax savings from the transaction are lower or if the time horizon over which the transaction can be executed is longer. Deferral is also increasing in cost of a future unfavorable event to which the irreversibility of the transaction limits one's ability to respond, but may increase or decrease with a change in the probability that an unfavorable event occurs. We apply the model to a common estate freeze tax plan in Canada. Undertaking an estate freeze requires a private company's owner-manager to choose how one's business assets are to be distributed at death. In contrast to the conventional wisdom regarding the timing of this strategy, we find that waiting to implement the strategy is often optimal. We test the model using data on family-owned businesses in Canada and find strong support for the model's predictions.


2020 ◽  
pp. 088626052097582
Author(s):  
Saeed Kabiri ◽  
Jaeyong Choi ◽  
Seyyedeh Masoomeh (Shamila) Shadmanfaat ◽  
Julak Lee

The role of routine activity theory (RAT) as a guiding theoretical approach to understand online victimization has been well documented. However, the recent emphasis in criminology on its applicability to online victimization has largely been based on evidence from Anglo-American studies. This study fills this gap by testing the predictive utility of RAT for cyberstalking victimization, using data from a sample of female Iranian students. Our structural equation model showed that online exposure to motivated offenders, target suitability, and ineffective online guardianship were positively and significantly associated with cyberstalking victimization. Our results provide strong support for RAT, indicating its generalizability to a different sociopolitical context.


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