Department of Evolution and Ecology, University of California, One Shields Avenue, Davis, CA 95616, USA.
J Biol Dyn. 2011 Mar;5(2):120-34. doi: 10.1080/17513758.2010.525667.
Organisms modulate their fitness in heterogeneous environments by dispersing. Prior work shows that there is selection against 'unconditional' dispersal in spatially heterogeneous environments. 'Unconditional' means individuals disperse at a rate independent of their location. We prove that if within-patch fitness varies spatially and between two values temporally, then there is selection for unconditional dispersal: any evolutionarily stable strategy (ESS) or evolutionarily stable coalition (ESC) includes a dispersive phenotype. Moreover, at this ESS or ESC, there is at least one sink patch (i.e. geometric mean of fitness less than one) and no sources patches (i.e. geometric mean of fitness greater than one). These results coupled with simulations suggest that spatial-temporal heterogeneity is due to abiotic forcing result in either an ESS with a dispersive phenotype or an ESC with sedentary and dispersive phenotypes. In contrast, the spatial-temporal heterogeneity due to biotic interactions can select for higher dispersal rates that ultimately spatially synchronize population dynamics.
生物通过扩散来调节其在异质环境中的适应性。先前的研究表明，在空间异质环境中存在对“无条件”扩散的选择压力。“无条件”是指个体以与位置无关的速度扩散。我们证明，如果斑块内的适应性在空间上和在两个时间上随时间变化，则无条件扩散是有利的选择：任何进化稳定策略（ESS）或进化稳定联盟（ESC）都包含一种扩散表型。此外，在这个 ESS 或 ESC 中，至少有一个汇斑块（即适应性的几何平均值小于 1）和没有源斑块（即适应性的几何平均值大于 1）。这些结果结合模拟表明，时空异质性是由于非生物胁迫导致的，结果是具有扩散表型的 ESS 或具有定居和扩散表型的 ESC。相比之下，由于生物相互作用引起的时空异质性可以选择更高的扩散率，最终使种群动态在空间上同步。
