Evolution Letters最新文献

{"title":"Equilibria and oscillations in cheat-cooperator dynamics.","authors":"Ming Liu, Geoff Wild, Stuart A West","doi":"10.1093/evlett/qrad032","DOIUrl":"10.1093/evlett/qrad032","url":null,"abstract":"<p><p>Cooperative societies can be threatened by cheats, who invest less in cooperation and exploit the contributions of others. The impact of cheats depends on the extent to which they are maintained in the population. However, different empirical studies, across organisms ranging from RNA replicators to bacteria, have shown diverse cheat-cooperator dynamics. These vary from approaching a stable equilibrium to dynamic cyclical oscillations. The reason for this variation remains unclear. Here, we develop a theoretical model to identify the factors that determine whether dynamics should tend toward stable equilibria or cyclical oscillations. Our analyses show that (1) a combination of both periodic population bottlenecks and density-dependent selection on cheating is required to produce cyclical oscillations and (2) the extent of frequency-dependent selection for cheating can influence the amplitude of these oscillations but does not lead to oscillations alone. Furthermore, we show that stochastic group formation (demographic stochasticity) can generate different forms of oscillation, over a longer time scale, across growth cycles. Our results provide experimentally testable hypotheses for the processes underlying cheat-cooperator dynamics.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 5","pages":"339-350"},"PeriodicalIF":5.0,"publicationDate":"2023-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10565900/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41216625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pleistocene glaciations caused the latitudinal gradient of within-species genetic diversity.","authors":"Emanuel M Fonseca,&nbsp;Tara A Pelletier,&nbsp;Sydney K Decker,&nbsp;Danielle J Parsons,&nbsp;Bryan C Carstens","doi":"10.1093/evlett/qrad030","DOIUrl":"10.1093/evlett/qrad030","url":null,"abstract":"<p><p>Intraspecific genetic diversity is a key aspect of biodiversity. Quaternary climatic change and glaciation influenced intraspecific genetic diversity by promoting range shifts and population size change. However, the extent to which glaciation affected genetic diversity on a global scale is not well established. Here we quantify nucleotide diversity, a common metric of intraspecific genetic diversity, in more than 38,000 plant and animal species using georeferenced DNA sequences from millions of samples. Results demonstrate that tropical species contain significantly more intraspecific genetic diversity than nontropical species. To explore potential evolutionary processes that may have contributed to this pattern, we calculated summary statistics that measure population demographic change and detected significant correlations between these statistics and latitude. We find that nontropical species are more likely to deviate from neutral expectations, indicating that they have historically experienced dramatic fluctuations in population size likely associated with Pleistocene glacial cycles. By analyzing the most comprehensive data set to date, our results imply that Quaternary climate perturbations may be more important as a process driving the latitudinal gradient in species richness than previously appreciated.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 5","pages":"331-338"},"PeriodicalIF":5.0,"publicationDate":"2023-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/dd/12/qrad030.PMC10565891.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41216635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Signatures of kin selection in a natural population of the bacteria <i>Bacillus subtilis</i>.","authors":"Laurence J Belcher, Anna E Dewar, Chunhui Hao, Melanie Ghoul, Stuart A West","doi":"10.1093/evlett/qrad029","DOIUrl":"10.1093/evlett/qrad029","url":null,"abstract":"<p><p>Laboratory experiments have suggested that bacteria perform a range of cooperative behaviors, which are favored because they are directed toward relatives (kin selection). However, there is a lack of evidence for cooperation and kin selection in natural bacterial populations. Molecular population genetics offers a promising method to study natural populations because the theory predicts that kin selection will lead to relaxed selection, which will result in increased polymorphism and divergence at cooperative genes. Examining a natural population of <i>Bacillus subtilis</i>, we found consistent evidence that putatively cooperative traits have higher polymorphism and greater divergence than putatively private traits expressed at the same rate. In addition, we were able to eliminate alternative explanations for these patterns and found more deleterious mutations in genes controlling putatively cooperative traits. Overall, our results suggest that cooperation is favored by kin selection, with an average relatedness of <i>r</i> = .79 between interacting individuals.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 5","pages":"315-330"},"PeriodicalIF":5.0,"publicationDate":"2023-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10565896/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41216636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ancient hybridization leads to the repeated evolution of red flowers across a monkeyflower radiation.","authors":"Aidan W Short,&nbsp;Matthew A Streisfeld","doi":"10.1093/evlett/qrad024","DOIUrl":"10.1093/evlett/qrad024","url":null,"abstract":"<p><p>The reuse of old genetic variation can promote rapid diversification in evolutionary radiations, but in most cases, the historical events underlying this divergence are not known. For example, ancient hybridization can generate new combinations of alleles that sort into descendant lineages, potentially providing the raw material to initiate divergence. In the <i>Mimulus aurantiacus</i> species complex, there is evidence for widespread gene flow among members of this radiation. In addition, allelic variation in the <i>MaMyb2</i> gene is responsible for differences in flower color between the closely related ecotypes of subspecies <i>puniceus</i>, contributing to reproductive isolation by pollinators. Previous work suggested that <i>MaMyb2</i> was introgressed into the red-flowered ecotype of <i>puniceus</i>. However, additional taxa within the radiation have independently evolved red flowers from their yellow-flowered ancestors, raising the possibility that this introgression had a more ancient origin. In this study, we used repeated tests of admixture from whole-genome sequence data across this diverse radiation to demonstrate that there has been both ancient and recurrent hybridization in this group. However, most of the signal of this ancient introgression has been removed due to selection, suggesting that widespread barriers to gene flow are in place between taxa. Yet, a roughly 30 kb region that contains the <i>MaMyb2</i> gene is currently shared only among the red-flowered taxa. Patterns of admixture, sequence divergence, and extended haplotype homozygosity across this region confirm a history of ancient hybridization, where functional variants have been preserved due to positive selection in red-flowered taxa but lost in their yellow-flowered counterparts. The results of this study reveal that selection against gene flow can reduce genomic signatures of ancient hybridization, but that historical introgression can provide essential genetic variation that facilitates the repeated evolution of phenotypic traits between lineages.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 5","pages":"293-304"},"PeriodicalIF":5.0,"publicationDate":"2023-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10565894/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41216624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The evolutionary demise of a social interaction: experimentally induced loss of traits involved in the supply and demand of care.","authors":"Eleanor K Bladon,&nbsp;Sonia Pascoal,&nbsp;Nancy Bird,&nbsp;Rahia Mashoodh,&nbsp;Rebecca M Kilner","doi":"10.1093/evlett/qrad016","DOIUrl":"https://doi.org/10.1093/evlett/qrad016","url":null,"abstract":"<p><p>Phenotypic plasticity enables animals to adjust their behavior flexibly to their social environment-sometimes through the expression of adaptive traits that have not been exhibited for several generations. We investigated how long social adaptations can usefully persist when they are not routinely expressed, by using experimental evolution to document the loss of social traits associated with the supply and demand of parental care. We allowed populations of burying beetles <i>Nicrophorus vespilloides</i> to evolve in two different social environments for 48 generations in the lab. In \"Full Care\" populations, traits associated with the supply and demand of parental care were expressed at every generation, whereas in \"No Care\" populations we prevented expression of these traits experimentally. We then revived trait expression in the No Care populations at generations 24, 43, and 48 by allowing parents to supply post-hatching care and compared these social traits with those expressed by the Full Care populations. We found that offspring demands for care and male provision of care in the No Care populations were lost sooner than female provision of care. We suggest that this reflects differences in the strength of selection for the expression of alternative traits in offspring, males and females, which can enhance fitness when post-hatching care is disrupted.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 3","pages":"168-175"},"PeriodicalIF":5.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10210443/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9547513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Divergent evolution of genetic sex determination mechanisms along environmental gradients.","authors":"Martijn A Schenkel,&nbsp;Jean-Christophe Billeter,&nbsp;Leo W Beukeboom,&nbsp;Ido Pen","doi":"10.1093/evlett/qrad011","DOIUrl":"https://doi.org/10.1093/evlett/qrad011","url":null,"abstract":"<p><p>Sex determination (SD) is a crucial developmental process, but its molecular underpinnings are very diverse, both between and within species. SD mechanisms have traditionally been categorized as either genetic (GSD) or environmental (ESD), depending on the type of cue that triggers sexual differentiation. However, mixed systems, with both genetic and environmental components, are more prevalent than previously thought. Here, we show theoretically that environmental effects on expression levels of genes within SD regulatory mechanisms can easily trigger within-species evolutionary divergence of SD mechanisms. This may lead to the stable coexistence of multiple SD mechanisms and to spatial variation in the occurrence of different SD mechanisms along environmental gradients. We applied the model to the SD system of the housefly, a global species with world-wide latitudinal clines in the frequencies of different SD systems, and found that it correctly predicted these clines if specific genes in the housefly SD system were assumed to have temperature-dependent expression levels. We conclude that environmental sensitivity of gene regulatory networks may play an important role in diversification of SD mechanisms.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 3","pages":"132-147"},"PeriodicalIF":5.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10210438/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9599580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of recognition error in the stability of green-beard genes.","authors":"Jibeom Choi,&nbsp;Seoeun Lee,&nbsp;Hyun Kim,&nbsp;Junpyo Park","doi":"10.1093/evlett/qrad012","DOIUrl":"https://doi.org/10.1093/evlett/qrad012","url":null,"abstract":"<p><p>The empirical examples of the green-beard genes, once a conundrum of evolutionary biology, are accumulating, while theoretical analyses of this topic are occasional compared to those concerning (narrow-sense) kin selection. In particular, the recognition error of the green-beard effect that the cooperator fails to accurately recognize the other cooperators or defectors is readily found in numerous green-beard genes. To our knowledge, however, no model up to date has taken that effect into account. In this article, we investigated the effect of recognition error on the fitness of the green-beard gene. By employing theories of evolutionary games, our mathematical model predicts that the fitness of the green-beard gene is frequency dependent (frequency of the green-beard gene), which was corroborated by experiments performed with yeast <i>FLO1</i>. The experiment also shows that the cells with the green-beard gene (<i>FLO1</i>) are sturdier under severe stress. We conclude that the low recognition error among the cooperators, the higher reward of cooperation, and the higher cost of defection confer an advantage to the green-beard gene under certain conditions, confirmed by numerical simulation as well. Interestingly, we expect that the recognition error to the defectors may promote the cooperator fitness if the cooperator frequency is low and mutual defection is detrimental. Our ternary approach of mathematical analysis, experiments, and simulation lays the groundwork of the standard model for the green-beard gene that can be generalized to other species.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 3","pages":"157-167"},"PeriodicalIF":5.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/b6/6a/qrad012.PMC10210436.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9547512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting evolution in experimental range expansions of an aquatic model system.","authors":"Giacomo Zilio,&nbsp;Sascha Krenek,&nbsp;Claire Gougat-Barbera,&nbsp;Emanuel A Fronhofer,&nbsp;Oliver Kaltz","doi":"10.1093/evlett/qrad010","DOIUrl":"https://doi.org/10.1093/evlett/qrad010","url":null,"abstract":"<p><p>Predicting range expansion dynamics is an important goal of both fundamental and applied research in conservation and global change biology. However, this is challenging if ecological and evolutionary processes occur on the same time scale. Using the freshwater ciliate <i>Paramecium caudatum</i>, we combined experimental evolution and mathematical modeling to assess the predictability of evolutionary change during range expansions. In the experiment, we followed ecological dynamics and trait evolution in independently replicated microcosm populations in range core and front treatments, where episodes of natural dispersal alternated with periods of population growth. These eco-evolutionary conditions were recreated in a predictive mathematical model, parametrized with dispersal and growth data of the 20 founder strains in the experiment. We found that short-term evolution was driven by selection for increased dispersal in the front treatment and general selection for higher growth rates in all treatments. There was a good quantitative match between predicted and observed trait changes. Phenotypic divergence was further mirrored by genetic divergence between range core and front treatments. In each treatment, we found the repeated fixation of the same cytochrome c oxidase I (COI) marker genotype, carried by strains that also were the most likely winners in our model. Long-term evolution in the experimental range front lines resulted in the emergence of a dispersal syndrome, namely a competition-colonization trade-off. Altogether, both model and experiment highlight the potential importance of dispersal evolution as a driver of range expansions. Thus, evolution at range fronts may follow predictable trajectories, at least for simple scenarios, and predicting these dynamics may be possible from knowledge of few key parameters.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 3","pages":"121-131"},"PeriodicalIF":5.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/c9/86/qrad010.PMC10210439.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9547517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ornaments indicate parasite load only if they are dynamic or parasites are contagious.","authors":"Liam R Dougherty,&nbsp;Faith Rovenolt,&nbsp;Alexia Luyet,&nbsp;Jukka Jokela,&nbsp;Jessica F Stephenson","doi":"10.1093/evlett/qrad017","DOIUrl":"https://doi.org/10.1093/evlett/qrad017","url":null,"abstract":"<p><p>Choosing to mate with an infected partner has several potential fitness costs, including disease transmission and infection-induced reductions in fecundity and parental care. By instead choosing a mate with no, or few, parasites, animals avoid these costs and may also obtain resistance genes for offspring. Within a population, then, the quality of sexually selected ornaments on which mate choice is based should correlate negatively with the number of parasites with which a host is infected (\"parasite load\"). However, the hundreds of tests of this prediction yield positive, negative, or no correlation between parasite load and ornament quality. Here, we use phylogenetically controlled meta-analysis of 424 correlations from 142 studies on a wide range of host and parasite taxa to evaluate explanations for this ambiguity. We found that ornament quality is weakly negatively correlated with parasite load overall, but the relationship is more strongly negative among ornaments that can dynamically change in quality, such as behavioral displays and skin pigmentation, and thus can accurately reflect current parasite load. The relationship was also more strongly negative among parasites that can transmit during sex. Thus, the direct benefit of avoiding parasite transmission may be a key driver of parasite-mediated sexual selection. No other moderators, including methodological details and whether males exhibit parental care, explained the substantial heterogeneity in our data set. We hope to stimulate research that more inclusively considers the many and varied ways in which parasites, sexual selection, and epidemiology intersect.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 3","pages":"176-190"},"PeriodicalIF":5.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10210455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9550516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damaraland mole-rats do not rely on helpers for reproduction or survival.","authors":"Jack Thorley, Hanna M Bensch, Kyle Finn, Tim Clutton-Brock, Markus Zöttl","doi":"10.1093/evlett/qrad023","DOIUrl":"10.1093/evlett/qrad023","url":null,"abstract":"<p><p>In eusocial invertebrates and obligate cooperative breeders, successful reproduction is dependent on assistance from non-breeding group members. Although naked (<i>Heterocephalus glaber</i>) and Damaraland mole-rats (<i>Fukomys damarensis</i>) are often described as eusocial and their groups are suggested to resemble those of eusocial insects more closely than groups of any other vertebrate, the extent to which breeding individuals benefit from the assistance of non-breeding group members is unclear. Here we show that, in wild Damaraland mole-rats, prospective female breeders usually disperse and settle alone in new burrow systems where they show high survival rates and remain in good body condition-often for several years-before being joined by males. In contrast to many obligate cooperative vertebrates, pairs reproduced successfully without non-breeding helpers, and the breeding success of experimentally formed pairs was similar to that of larger, established groups. Though larger breeding groups recruited slightly more pups than smaller groups, adult survival was independent of group size and group size had mixed effects on the growth of non-breeders. Our results suggest that Damaraland mole-rats do not need groups to survive and that cooperative breeding in the species is not obligate as pairs can-and frequently do-reproduce without the assistance of helpers. While re-emphasizing the importance of ecological constraints on dispersal in social mole-rats, the mixed effects of group size in our study suggest that indirect benefits accrued through cooperative behavior may have played a less prominent role in the evolution of mole-rat group-living than previously thought.</p>","PeriodicalId":48629,"journal":{"name":"Evolution Letters","volume":"7 4","pages":"203-215"},"PeriodicalIF":3.4,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10355180/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10207788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}