共查询到20条相似文献,搜索用时 0 毫秒
1.
Masakado Kawata 《Ecological Research》1998,13(3):367-375
A computer simulation was conducted to examine the effect of differential dispersal of sexes on the evolution of altruism in viscous populations. First, a basic model, which was regarded as a purely viscous population model, was constructed. The model was assumed to be the same as the simulation model of Wilson etal. (1992), except that it assumed sexual reproduction and that only females show altruistic behavior toward females. For the basic model, altruism could not evolve when b/Nc, where b is the benefit of the altruism to the recipient, c is the cost to the altruist, and N is the number of interacting neighbors. The male dispersal model I assumed that females disperse to nine neighboring sites including the natal site, but males disperse to eight sites farther than females do. For this model, altruistic alleles could evolve when b/N was equal to c or b/N was slightly smaller than c only when the male dispersal distance was slightly larger than those of females. The male dispersal model II assumed that the male dispersal distance follows a normal probability distribution. The Vole model was based on actual data of the gray-sided vole, Clethironomys rufocanus bedfordiae, whose frequency distribution of dispersal distance was similar to a normal distribution. For these models, altruism could evolve under the condition that b/N was slightly smaller than c when the dispersal distances of males were larger than those of females. The results indicate that the differential dispersal of sexes, in which females are philopatric and males disperse farther than females, can somewhat increase the probability of spreading altruistic alleles in viscous populations. 相似文献
2.
Lia Thomson;Daniel Priego Espinosa;Yaniv Brandvain;Jeremy Van Cleve; 《Ecology and evolution》2024,14(2):e10980
Much research on the evolution of altruism via kin selection, group selection, and reciprocity focuses on the role of a single locus or quantitative trait. Very few studies have explored how linked selection, or selection at loci neighboring an altruism locus, impacts the evolution of altruism. While linked selection can decrease the efficacy of selection at neighboring loci, it might have other effects including promoting selection for altruism by increasing relatedness in regions of low recombination. Here, we used population genetic simulations to study how negative selection at linked loci, or background selection, affects the evolution of altruism. When altruism occurs between full siblings, we found that background selection interfered with selection on the altruistic allele, increasing its fixation probability when the altruistic allele was disfavored and reducing its fixation when the allele was favored. In other words, background selection has the same effect on altruistic genes in family-structured populations as it does on other, nonsocial, genes. This contrasts with prior research showing that linked selective sweeps can favor the evolution of cooperation, and we discuss possibilities for resolving these contrasting results. 相似文献
3.
One of the enduring puzzles in biology and the social sciences is the origin and persistence of intraspecific cooperation and altruism in humans and other species. Hundreds of theoretical models have been proposed and there is much confusion about the relationship between these models. To clarify the situation, we developed a synthetic conceptual framework that delineates the conditions necessary for the evolution of altruism and cooperation. We show that at least one of the four following conditions needs to be fulfilled: direct benefits to the focal individual performing a cooperative act; direct or indirect information allowing a better than random guess about whether a given individual will behave cooperatively in repeated reciprocal interactions; preferential interactions between related individuals; and genetic correlation between genes coding for altruism and phenotypic traits that can be identified. When one or more of these conditions are met, altruism or cooperation can evolve if the cost-to-benefit ratio of altruistic and cooperative acts is greater than a threshold value. The cost-to-benefit ratio can be altered by coercion, punishment and policing which therefore act as mechanisms facilitating the evolution of altruism and cooperation. All the models proposed so far are explicitly or implicitly built on these general principles, allowing us to classify them into four general categories. 相似文献
4.
Peter D. Sozou 《Proceedings. Biological sciences / The Royal Society》2009,276(1669):2955-2962
Social discounting in economics involves applying a diminishing weight to community-wide benefits or costs into the future. It impacts on public policy decisions involving future positive or negative effects, but there is no consensus on the correct basis for determining the social discount rate. This study presents an evolutionary biological framework for social discounting. How an organism should value future benefits to its local community is governed by the extent to which members of the community in the future are likely to be its kin. Trade-offs between immediate and delayed benefits to an individual or to its community are analysed for a modelled patch-structured iteroparous population with limited dispersal. It is shown that the social discount rate is generally lower than the individual (private) discount rate. The difference in the two rates is most pronounced, in ratio terms, when the dispersal level is low and the hazard rate for patch destruction is much smaller than the individual mortality rate. When decisions involve enforced collective action rather than individuals acting independently, social investment increases but the social discount rate remains the same. 相似文献
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6.
Hiroshi Akashi 《Current opinion in genetics & development》2001,11(6):660-666
The combination of complete genome sequence information and estimates of mRNA abundances have begun to reveal causes of both silent and protein sequence evolution. Translational selection appears to explain patterns of synonymous codon usage in many prokaryotes as well as a number of eukaryotic model organisms (with the notable exception of vertebrates). Relationships between gene length and codon usage bias, however, remain unexplained. Intriguing correlations between expression patterns and protein divergence suggest some general mechanisms underlying protein evolution. 相似文献
7.
The validity and value of inclusive fitness theory 总被引:1,自引:0,他引:1
Bourke AF 《Proceedings. Biological sciences / The Royal Society》2011,278(1723):3313-3320
Social evolution is a central topic in evolutionary biology, with the evolution of eusociality (societies with altruistic, non-reproductive helpers) representing a long-standing evolutionary conundrum. Recent critiques have questioned the validity of the leading theory for explaining social evolution and eusociality, namely inclusive fitness (kin selection) theory. I review recent and past literature to argue that these critiques do not succeed. Inclusive fitness theory has added fundamental insights to natural selection theory. These are the realization that selection on a gene for social behaviour depends on its effects on co-bearers, the explanation of social behaviours as unalike as altruism and selfishness using the same underlying parameters, and the explanation of within-group conflict in terms of non-coinciding inclusive fitness optima. A proposed alternative theory for eusocial evolution assumes mistakenly that workers' interests are subordinate to the queen's, contains no new elements and fails to make novel predictions. The haplodiploidy hypothesis has yet to be rigorously tested and positive relatedness within diploid eusocial societies supports inclusive fitness theory. The theory has made unique, falsifiable predictions that have been confirmed, and its evidence base is extensive and robust. Hence, inclusive fitness theory deserves to keep its position as the leading theory for social evolution. 相似文献
8.
Samuel J. Lymbery Blake Wyber Joseph L. Tomkins Leigh W. Simmons 《Journal of evolutionary biology》2020,33(7):966-978
The outcome of sexual conflict can depend on the social environment, as males respond to changes in the inclusive fitness payoffs of harmfulness and harm females less when they compete with familiar relatives. Theoretical models also predict that if limited male dispersal predictably enhances local relatedness while maintaining global competition, kin selection can produce evolutionary divergences in male harmfulness among populations. Experimental tests of these predictions, however, are rare. We assessed rates of dispersal in female and male seed beetles Callosobruchus maculatus, a model species for studies of sexual conflict, in an experimental setting. Females dispersed significantly more often than males, but dispersing males travelled just as far as dispersing females. Next, we used experimental evolution to test whether limiting dispersal allowed the action of kin selection to affect divergence in male harmfulness and female resistance. Populations of C. maculatus were evolved for 20 and 25 generations under one of three dispersal regimens: completely free dispersal, limited dispersal and no dispersal. There was no divergence among treatments in female reproductive tract scarring, ejaculate size, mating behaviour, fitness of experimental females mated to stock males or fitness of stock females mated to experimental males. We suggest that this is likely due to insufficient strength of kin selection rather than a lack of genetic variation or time for selection. Limited dispersal alone is therefore not sufficient for kin selection to reduce male harmfulness in this species, consistent with general predictions that limited dispersal will only allow kin selection if local relatedness is independent of the intensity of competition among kin. 相似文献
9.
《Ethology, Ecology and Evolution》2012,24(3):217-231
Most models describing the evolution of animal cooperative behaviour are based on the principle of reciprocal altruism. However, according to the “advertising hypothesisrdquo;, based on Zahavi's handicap principle, an altruistic act is a signal indicating an individual's quality and is profitable even if its recipient never reciprocates. In this paper, this hypothesis has been tested in three computer simulations of the evolution of altruistic behaviour. A model of a population has been studied, where individuals' fitness was calculated as a product of two parameters: “energy” and “prestige”. It was assumed that as a result of an altruistic act its donor loses energy and gains prestige, and a recipient gains energy and loses prestige. Individuals played a game based on decision-making: to cooperate (i.e. to behave altruistically) or not in a particular round. An individual's strategy influenced its fitness, i.e. the number of its offspring. As offspring inherited their parent's strategy, frequency of “good” strategies increased in the population, and “bad” ones disappeared. The results of these simulations show that if altruistic acts are costly and bring social prestige, cooperation can persist in the population under a wide range of conditions, despite the lack of direct reciprocity. However, besides the strategy of cooperation with a frequency proportional to an individual's quality, as predicted by the advertising hypothesis, other strategies, even unconditional altruism, can persist in the population in some conditions. 相似文献
10.
Rolf Kümmerli Ashleigh S. Griffin Stuart A. West Angus Buckling Freya Harrison 《Proceedings. Biological sciences / The Royal Society》2009,276(1672):3531-3538
There has been extensive theoretical debate over whether population viscosity (limited dispersal) can favour cooperation. While limited dispersal increases the probability of interactions occurring between relatives, which can favour cooperation, it can also lead to an increase in competition between relatives and this can reduce or completely negate selection for cooperation. Despite much theoretical attention, there is a lack of empirical research investigating these issues. We cultured Pseudomonas aeruginosa bacteria in medium with different degrees of viscosity and examined the fitness consequences for a cooperative trait—the production of iron-scavenging siderophore molecules. We found that increasing viscosity of the growth medium (i) significantly limited bacterial dispersal and the diffusion of siderophore molecules and (ii) increased the fitness of individuals that produced siderophores relative to mutants that did not. We propose that viscosity favours siderophore-producing individuals in this system, because the benefits of siderophore production are more likely to accrue to relatives (i.e. greater indirect benefits), and, at the same time, bacteria are more likely to gain direct fitness benefits by taking up siderophore molecules produced by themselves (i.e. the trait becomes less cooperative). Our results suggest that viscosity of the microbial growth environment is a crucial factor determining the dynamics of wild-type bacteria and siderophore-deficient mutants in natural habitats, such as the viscous mucus in cystic fibrosis lung. 相似文献
11.
Dispersal provides the opportunity to escape harm and colonize new patches, enabling populations to expand and persist. However, the benefits of dispersal associated with escaping harm will be dependent on the structure of the environment and the likelihood of escape. Here, we empirically investigate how the spatial distribution of a parasite influences the evolution of host dispersal. Bacteriophages are a strong and common threat for bacteria in natural environments and offer a good system with which to explore parasite‐mediated selection on host dispersal. We used two transposon mutants of the opportunistic bacteria, Pseudomonas aeruginosa, which varied in their motility (a disperser and a nondisperser), and the lytic bacteriophage ФKZ. The phage was distributed either in the central point of colony inoculation only, thus offering an escape route for the dispersing bacteria; or, present throughout the agar, where benefits of dispersal might be lost. Surprisingly, we found dispersal to be equally advantageous under both phage conditions relative to when phages were absent. A general explanation is that dispersal decreased the spatial structuring of host population, reducing opportunities for parasite transmission, but other more idiosyncratic mechanisms may also have contributed. This study highlights the crucial role the parasites can play on the evolution of dispersal and, more specifically, that bacteriophages, which are ubiquitous, are likely to select for bacterial motility. 相似文献
12.
Jeff Clune Heather J. Goldsby Charles Ofria Robert T. Pennock 《Proceedings. Biological sciences / The Royal Society》2011,278(1706):666-674
Inclusive fitness theory predicts that natural selection will favour altruist genes that are more accurate in targeting altruism only to copies of themselves. In this paper, we provide evidence from digital evolution in support of this prediction by competing multiple altruist-targeting mechanisms that vary in their accuracy in determining whether a potential target for altruism carries a copy of the altruist gene. We compete altruism-targeting mechanisms based on (i) kinship (kin targeting), (ii) genetic similarity at a level greater than that expected of kin (similarity targeting), and (iii) perfect knowledge of the presence of an altruist gene (green beard targeting). Natural selection always favoured the most accurate targeting mechanism available. Our investigations also revealed that evolution did not increase the altruism level when all green beard altruists used the same phenotypic marker. The green beard altruism levels stably increased only when mutations that changed the altruism level also changed the marker (e.g. beard colour), such that beard colour reliably indicated the altruism level. For kin- and similarity-targeting mechanisms, we found that evolution was able to stably adjust altruism levels. Our results confirm that natural selection favours altruist genes that are increasingly accurate in targeting altruism to only their copies. Our work also emphasizes that the concept of targeting accuracy must include both the presence of an altruist gene and the level of altruism it produces. 相似文献
13.
Phylogenetic studies of geographic range evolution are increasingly using statistical model selection methods to choose among variants of the dispersal‐extinction‐cladogenesis (DEC) model, especially between DEC and DEC+J, a variant that emphasizes “jump dispersal,” or founder‐event speciation, as a type of cladogenetic range inheritance scenario. Unfortunately, DEC+J is a poor model of founder‐event speciation, and statistical comparisons of its likelihood with DEC are inappropriate. DEC and DEC+J share a conceptual flaw: cladogenetic events of range inheritance at ancestral nodes, unlike anagenetic events of dispersal and local extinction along branches, are not modelled as being probabilistic with respect to time. Ignoring this probability factor artificially inflates the contribution of cladogenetic events to the likelihood, and leads to underestimates of anagenetic, time‐dependent range evolution. The flaw is exacerbated in DEC+J because not only is jump dispersal allowed, expanding the set of cladogenetic events, its probability relative to non‐jump events is assigned a free parameter, j, that when maximized precludes the possibility of non‐jump events at ancestral nodes. DEC+J thus parameterizes the mode of speciation, but like DEC, it does not parameterize the rate of speciation. This inconsistency has undesirable consequences, such as a greater tendency towards degenerate inferences in which the data are explained entirely by cladogenetic events (at which point branch lengths become irrelevant, with estimated anagenetic rates of 0). Inferences with DEC+J can in some cases depart dramatically from intuition, e.g. when highly unparsimonious numbers of jump dispersal events are required solely because j is maximized. Statistical comparison with DEC is inappropriate because a higher DEC+J likelihood does not reflect a more close approximation of the “true” model of range evolution, which surely must include time‐dependent processes; instead, it is simply due to more weight being allocated (via j) to jump dispersal events whose time‐dependent probabilities are ignored. In testing hypotheses about the geographic mode of speciation, jump dispersal can and should instead be modelled using existing frameworks for state‐dependent lineage diversification in continuous time, taking appropriate cautions against Type I errors associated with such methods. For simple inference of ancestral ranges on a fixed phylogeny, a DEC‐based model may be defensible if statistical model selection is not used to justify the choice, and it is understood that inferences about cladogenetic range inheritance lack any relation to time, normally a fundamental axis of evolutionary models. 相似文献
14.
Tadeusz J. Kawecki 《Journal of evolutionary biology》1991,4(3):487-500
A verbal model is presented for a mechanism that enhances the probability of the evolution of altruism in diploids if the gene for altruism arises on the X chromosome. If the altruism takes place between sibs of the homogametic sex, the condition for spread of a sex-linked gene for altruism is less stringent than for an autosomal gene. Then, with altruistic behavior present, selection for increased efficiency (benefit/cost ratio) may raise the efficiency above the autosomal threshold before autosomal modifiers are widespread enough to eliminate the behavior. The results of computer simulations confirms that, if the initial benefit/cost ratio is lower than 2, sex-linkage can make the evolution of altruism more likely. 相似文献
15.
Reproductive division of labour is common in many societies, including those of eusocial insects, cooperatively breeding vertebrates, and most forms of multicellularity. However, conflict over what is best for the individual vs. the group can prevent an optimal division of labour from being achieved. In the social amoeba Dictyostelium discoideum, cells aggregate to become multicellular and a fraction behaves altruistically, forming a dead stalk that supports the rest. Theory suggests that intra‐organismal conflict over spore–stalk cell fate can drive rapid evolutionary change in allocation traits, leading to polymorphisms within populations or rapid divergence between them. Here, we assess several proxies for stalk size and spore–stalk allocation as metrics of altruism investment among strains and across geographic regions. We observe geographic divergence in stalk height that can be partly explained by differences in multicellular size, as well as variation among strains in clonal spore–stalk allocation, suggesting within‐population variation in altruism investment. Analyses of chimeras comprised of strains from the same vs. different populations indicated genotype‐by‐genotype epistasis, where the morphology of the chimeras deviated significantly from the average morphology of the strains developed clonally. The significantly negative epistasis observed for allopatric pairings suggests that populations are diverging in their spore–stalk allocation behaviours, generating incompatibilities when they encounter one another. Our results demonstrate divergence in microbial social traits across geographically separated populations and demonstrate how quantification of genotype‐by‐genotype interactions can elucidate the trajectory of social trait evolution in nature. 相似文献
16.
Andrew F. G. Bourke 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2014,369(1642)
Hamilton''s rule is a central theorem of inclusive fitness (kin selection) theory and predicts that social behaviour evolves under specific combinations of relatedness, benefit and cost. This review provides evidence for Hamilton''s rule by presenting novel syntheses of results from two kinds of study in diverse taxa, including cooperatively breeding birds and mammals and eusocial insects. These are, first, studies that empirically parametrize Hamilton''s rule in natural populations and, second, comparative phylogenetic analyses of the genetic, life-history and ecological correlates of sociality. Studies parametrizing Hamilton''s rule are not rare and demonstrate quantitatively that (i) altruism (net loss of direct fitness) occurs even when sociality is facultative, (ii) in most cases, altruism is under positive selection via indirect fitness benefits that exceed direct fitness costs and (iii) social behaviour commonly generates indirect benefits by enhancing the productivity or survivorship of kin. Comparative phylogenetic analyses show that cooperative breeding and eusociality are promoted by (i) high relatedness and monogamy and, potentially, by (ii) life-history factors facilitating family structure and high benefits of helping and (iii) ecological factors generating low costs of social behaviour. Overall, the focal studies strongly confirm the predictions of Hamilton''s rule regarding conditions for social evolution and their causes. 相似文献
17.
Johnstone RA 《Evolution; international journal of organic evolution》2008,62(10):2592-2599
In a spatially structured population, limited dispersal gives rise to local relatedness, potentially favoring indiscriminate helping behavior. However, it also leads to local competition, which reduces the benefits of helping local kin. This tension has become the focus for a growing body of theoretical work. Existing models, however, have focused chiefly on the net impact of limited dispersal on cooperative or competitive effort in a homogeneous population. Here, I extend existing models of kin selection in a group-structured population to allow for asymmetries in expected fecundity and reproductive success among group members. I explore the consequent impact of limited dispersal on the evolution of helping and harming behavior, and on the degree of reproductive inequality or skew. I show that when individuals in a group differ in their expected fecundity, limited dispersal gives rise to kin selection for harming behavior on the part of more fecund individuals, and for helping behavior on the part of less fecund individuals. As a result, philopatry tends to exaggerate differences in reproductive success, and so promotes greater reproductive skew. 相似文献
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19.
Abstract. Larval development of a small ovoviviparous comatulid crinoid, Aporometra wilsoni , was investigated using a population from South Australia. The genital pinnules of reproductive females each contain an ovary, within which are oocytes of various stages. Generally, one or more developing larvae lie outside the ovary, but within each pinnule. Larvae pass through \"uniformly ciliated\" and doliolaria stages before they exit the pinnule via the genital pore. The doliolariae lack the usual ciliary bands and are unable to swim. Doliolariae dissected from pinnules were followed through metamorphosis to the cystidean stage until the pentacrinoid larval stage. While previous reports on Aporometra have noted pentacrinoids attached to the female, virtually no pentacrinoids were found attached to any of the hundreds of adult females observed during this study. Females sampled from the mid-reproductive season (September and October) were found to bear >2500 developing eggs and larvae at a time. It appears that emerging doliolariae fall from the female and attach to other substrates to complete development. Aporometra is classified in Notocrinida with the Antarctic crinoid Notocrinus. This classification is based in part on their supposedly homologous larval brooding. However, the reproductive mechanism in A. wilsoni is quite different from Notocrinus , calling into question their current status as sister taxa. 相似文献
20.
The idea that cohesive groups, in which individuals help each other, have a competitive advantage over groups composed of selfish individuals has been widely suggested as an explanation for the evolution of cooperation in humans. Recent theoretical models propose the coevolution of parochial altruism and intergroup conflict, when in-group altruism and out-group hostility contribute to the group''s success in these conflicts. However, the few empirical attempts to test this hypothesis do not use natural groups and conflate measures of in-group and unbiased cooperative behaviour. We conducted field experiments based on naturalistic measures of cooperation (school/charity donations and lost letters'' returns) with two religious groups with an on-going history of conflict—Catholics and Protestants in Northern Ireland. Conflict was associated with reduced donations to out-group schools and the return of out-group letters, but we found no evidence that it influences in-group cooperation. Rather, socio-economic status was the major determinant of cooperative behaviour. Our study presents a challenge to dominant perspectives on the origins of human cooperation, and has implications for initiatives aiming to promote conflict resolution and social cohesion. 相似文献