Biology subjects

Gavrilets, S.

Publications and source records attributed to Gavrilets, S..

3 recordsLinked to original sources

bioRxiv2020

Ecological consequences of intraspecific variation in coevolutionary systems

The patterns and outcomes of coevolution are expected to depend on intraspecific trait variation. Various evolutionary factors can change this variation in time. As a result, modeling coevolutionary processes solely in terms of mean trait values may not be sufficient; one may need to study the dynamics of the whole trait distribution. Here, we develop a theoretical framework for studying the effects of evolving intraspecific variation in two-species coevolutionary systems. In particular, we build and study mathematical models of competition, exploiter-victim interactions, and mutualism in which the strength of within- and between-species interactions depends on the difference in continuously varying traits. We use analytical approximations based on the invasion analysis and supplement it with a numerical method. We find that intraspecific variation can be maintained if stabilizing selection is weak in at least one species. When intraspecific variation is maintained, stable coexistence is promoted by small ranges of interspecific interaction in two-species competition and mutualism, and large ranges in exploiter-victim interactions. We show that trait distributions can become multimodal. Our approach and results contribute to the understanding of the ecological consequences of intraspecific variation in coevolutionary systems by exploring its effects on population densities and trait distributions.

evolutionary biology↗

bioRxiv2019

Case studies and mathematical models of ecological speciation. V. Adaptive divergence of whitefish in Fennoscandia.

Modern speciation theory has greatly benefited from a variety of simple mathematical models focusing on the conditions and patterns of speciation and diversification in the presence of gene flow. Unfortunately the application of general theoretical concepts and tools to specific ecological systems remains a challenge. Here we apply modeling tools to better understand adaptive divergence of whitefish during the postglacial period in lakes of northern Fennoscandia. These lakes harbor up to three different morphs associated with the three major lake habitats: littoral, pelagic, and profundal. Using large-scale individual-based simulations, we aim to identify factors required for in situ emergence of the pelagic and profundal morphs in lakes initially colonized by the littoral morph. The importance of some of the factors we identify and study - sufficiently large levels of initial genetic variation, size- and habitat-specific mating, sufficiently large carrying capacity of the new niche - is already well recognized. In addition, our model also points to two other factors that have been largely disregarded in theoretical studies: fitness-dependent dispersal and strong predator pressure in the ancestral niche coupled with the lack of it in the new niche(s). We use our theoretical results to speculate about the process of diversification of whitefish in Fennoscandia and to identify potentially profitable directions for future empirical research.

evolutionary biology↗

bioRxiv2019

On the evolution of sexual receptivity in female primates

There has been much interest in the evolutionary forces responsible for, and underlying the diversity in, female primate reproductive cycles. Some primate species are like humans, sexually receptive to mating throughout their entire estrus cycle, while other species are the opposite, receptive for mere hours out of their several-week cycles. Why is there such prominent variation in sexual receptivity length among primate species? Here we examine the evolutionary trade-offs associated with sexual receptivity length using mathematical modeling. We investigate how various factors, including having ovulation signs present vs. concealed ovulation, female physiological costs, and group size, each influence the length of females receptive periods. We find that both continuous receptivity and very short lengths of receptivity are able to evolve. Our model predicts that increasing the impacts of infanticide will increase the length of the female receptive period, emphasizing the possible importance of paternity confusion. Similar effects can also be achieved by increasing the non-genetic benefits provided by males. Overall, our work offers a theoretical framework for understanding the evolution and diversity of mating traits in female primates.

evolutionary biology↗