Kisdi Eva
Department of Mathematics and Statistics, University of Helsinki, PO Box 68, FIN-00014, Finland.
J Theor Biol. 2016 Mar 7;392:69-82. doi: 10.1016/j.jtbi.2015.12.006. Epub 2015 Dec 29.
In fragmented but temporally stable landscapes, kin competition selects for dispersal when habitat patches are small, whereas the loss of dispersal is favoured when dispersal is costly and local populations are large enough for kin interactions to be negligible. In heterogeneous landscapes with both small and large patches, contrasting levels of kin competition facilitate the coexistence of low-dispersal and high-dispersal strategies. In this paper, I use both adaptive dynamics and inclusive fitness to analyse the evolution of dispersal in a simple model assuming that each patch supports either a single individual or a large population. With this assumption, many results can be obtained analytically. If the fraction of individuals living in small patches is below a threshold, then evolutionary branching yields two coexisting dispersal strategies. An attracting and evolutionarily stable dimorphism always exists (also when the monomorphic population does not have a branching point), and contains a strategy with zero dispersal and a strategy with dispersal probability between one half and the ESS of the classic Hamilton-May model. The present model features surprisingly rich population dynamics with multiple equilibria and unprotected dimorphisms, but the evolutionarily stable dimorphism is always protected.
在破碎但时间上稳定的景观中，当栖息地斑块较小时，亲缘竞争会促使扩散；而当扩散成本高昂且当地种群足够大以至于亲缘相互作用可忽略不计时，扩散的丧失则受到青睐。在既有小斑块又有大斑块的异质景观中，不同程度的亲缘竞争促进了低扩散和高扩散策略的共存。在本文中，我使用适应性动力学和广义适合度，在一个简单模型中分析扩散的进化，该模型假设每个斑块要么支持单个个体，要么支持大量种群。基于这个假设，可以通过解析得到许多结果。如果生活在小斑块中的个体比例低于某个阈值，那么进化分支会产生两种共存的扩散策略。总是存在一种吸引且进化稳定的二态性（当单态种群没有分支点时也是如此），并且包含一种零扩散策略和一种扩散概率介于二分之一与经典汉密尔顿 - 梅模型的ESS之间的策略。本模型具有令人惊讶的丰富种群动态，具有多个平衡点和无保护的二态性，但进化稳定的二态性总是受到保护的。
