Cherry Joshua L
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Genetics. 2003 Jun;164(2):789-95. doi: 10.1093/genetics/164.2.789.
In a subdivided population, local extinction and subsequent recolonization affect the fate of alleles. Of particular interest is the interaction of this force with natural selection. The effect of selection can be weakened by this additional source of stochastic change in allele frequency. The behavior of a selected allele in such a population is shown to be equivalent to that of an allele with a different selection coefficient in an unstructured population with a different size. This equivalence allows use of established results for panmictic populations to predict such quantities as fixation probabilities and mean times to fixation. The magnitude of the quantity N(e)s(e), which determines fixation probability, is decreased by extinction and recolonization. Thus deleterious alleles are more likely to fix, and advantageous alleles less likely to do so, in the presence of extinction and recolonization. Computer simulations confirm that the theoretical predictions of both fixation probabilities and mean times to fixation are good approximations.
在一个细分的种群中，局部灭绝和随后的重新定殖会影响等位基因的命运。特别令人感兴趣的是这种力量与自然选择之间的相互作用。等位基因频率这种额外的随机变化来源会削弱选择的效果。在这样一个种群中，一个被选择的等位基因的行为被证明等同于在一个不同大小的非结构化种群中具有不同选择系数的等位基因的行为。这种等效性使得可以利用针对随机交配种群的既定结果来预测诸如固定概率和平均固定时间等数量。决定固定概率的数量N(e)s(e)的大小会因灭绝和重新定殖而减小。因此，在存在灭绝和重新定殖的情况下，有害等位基因更有可能固定，而有利等位基因则不太可能固定。计算机模拟证实，固定概率和平均固定时间的理论预测都是很好的近似值。
