Evolution of variance in offspring number: the effects of population size and migration.
Evolution of variance in offspring number: the effects of population size and migration.
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后代数量方差的演变：种群规模和迁移的影响。
DOI：
10.1016/j.thbio.2005.05.003
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Shpak,Max
中科院分区：
文献类型：
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作者：
Shpak,Max
吉莱斯皮[1974]展示了这一点。上午好。纳特。108,145-151]，如果两个基因型产生相同的平均后代数，但在每一代内具有不同的方差，则方差较小的基因型将具有较高的有效适应度。具体而言，有效适应度为{ei65-1}，其中为平均适应度，{ei65-2}为子代数方差，N为总种群规模。该模型还预测，如果一种策略具有比竞争对手更高的算术平均适应度和更高的方差，则选择的结果将取决于种群规模(较大的种群规模有利于高方差、高平均基因型)。这表明，对于有利于高方差、高平均基因型的集合种群大小而言)。这表明，对于具有大量(相对)小种群的集合种群，如果迁移率较低，则可能倾向于采用方差和均值较低的策略，而较高的迁移率(与较大的有效种群规模一致)有利于相反的策略。以个人为基础的模拟证实，这确实是岛屿移徙模式的情况，尽管移徙的影响大不相同，取决于移徙是先于选择还是在选择之后。附录中指出，虽然吉莱斯皮[1974]。上午好。纳特。108,145-151]似乎确实是启发式的准确，但不清楚有效适合度的定义是从他的推导而来的。
It was shown by Gillespie [1974. Am. Nat. 108, 145–151], that if two genotypes produce the same average number of offspring on but have a different variance associated within each generation, the genotype with a lower variance will have a higher effective fitness. Specifically, the effective fitness is {ei65-1}, wherewis the mean fitness, {ei65-2} is the variance in offspring number, andNis the total population size. The model also predicts that if a strategy has a higher arithmetic mean fitness and a higher variance than the competitor, the outcome of selection will depend on the population size (with larger population sizes favoring the highvariance, high-mean genotype). This suggests that for metapopulation sizes favoring the high-variance, high-mean genotype). This suggests that for metapopulations with large numbers of (relatively) small demes, a strategy with lower variance and lower mean may be favored if the migration rate is low while higher migration rates (consistent with a larger effective population size) favor the opposite strategy. Individual-based simulation confirms that this is indeed the case for an island model of migration, though the effect of migration differs greatly depending on whether migration precedes or follows selection. It is noted in the appendix that while Gillespie [1974. Am. Nat. 108, 145–151] does seem to be heuristically accurate, it is not clear that the definition of effective fitness follows from his derivation.