Schreiber Sebastian J
Department of Evolution and Ecology, University of California, Davis, California 95616.
Am Nat. 2015 Dec;186(6):792-6. doi: 10.1086/683657. Epub 2015 Oct 30.
In the 1970s, John Gillespie introduced two principles in which evolution selects for genotypes with lower variation in offspring numbers. First, if the variation in offspring number primarily occurs within generations, the strength of this selective force is inversely proportional to population size. Second, if this variation primarily occurs between generations, the strength of this selective force is proportional to the variance and independent of population size. These principles lie at the core of bet-hedging theory. Using the common currency of fixation probabilities, I derive a general principle for which within-generation correlation of individual fitness acts as a dial between Gillespie's limiting cases. At low correlations, within-generation variation is the primary selective force. At high correlations, between-generation variation is the dominant selective force. As corollary of this general principle, selection for diversified bet-hedging strategies is shown to require higher within-generation environmental correlations in smaller populations.
20世纪70年代，约翰·吉莱斯皮提出了两条原则，即进化选择后代数量变异较小的基因型。第一，如果后代数量的变异主要发生在代内，这种选择力的强度与种群大小成反比。第二，如果这种变异主要发生在代际之间，这种选择力的强度与方差成正比，且与种群大小无关。这些原则是风险对冲理论的核心。使用固定概率这一通用货币，我推导出了一条通用原则，即个体适应度的代内相关性在吉莱斯皮的极限情况之间起到了一个调节器的作用。在低相关性时，代内变异是主要的选择力。在高相关性时，代际变异是主导的选择力。作为这一通用原则的推论，研究表明，在较小种群中，对多样化风险对冲策略的选择需要更高的代内环境相关性。
