Evolution of coalescence times, genetic diversity and structure during colonization
Evolution of coalescence times, genetic diversity and structure during colonization
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DOI：
10.1006/tpbi.1997.1302
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发表时间：
1997-04-01
影响因子：
1.4
通讯作者：
Gouyon, PH
中科院分区：
文献类型：
--
作者：
Austerlitz, F;JungMuller, B;Gouyon, PH
我们考虑了殖民化过程对地理细分种群的遗传多样性和空间结构的影响。结合聚结理论，采用踏脚石模型对序列发散和遗传参数的演化进行了预测。我们首先在一个经历逻辑增长的种群中得到合并时间的分析结果，然后我们考虑一个垫脚石模型，在这个模型中，从位于元种群边界之一的第一个种群开始，各个种群被连续地殖民化。我们使用递归方程来计算两个基因的聚结时间，选择在相同的deme或在不同的deme。这使我们可以得到聚并时间的分布和期望，并由此推导出平均两两差的分布和F-st的演化。我们的结果反映了创始人效应的影响，随着deme与第一个deme的距离增加，该效应变得更强。迁移率或生长率的增加通常会导致奠基者效应的减弱。F-st (i)在定植开始时增加，（ii）在迁移造成均质化时减少，（iii）再次向平衡值增加。序列间的双聚结时间或序列间差异的分布在定殖时期有一个高峰。这些结果可以帮助检测自然种群中的前殖民事件。(C) 1997学术出版社。
We consider the impact of a colonization process on the genetic diversity and spatial structure of a geographically subdivided population. A stepping-stone model combined with coalescence theory is used to predict the evolution of sequence divergence and genetic parameters. We first derive analytical results for coalescence times in a population undergoing logistic growth, We next consider a stepping-stone model in which demes are successively colonized, starting from a first deme at one of the borders of the metapopulation. We use recurrence equations to calculate coalescence times for two genes chosen either inside the same deme or in different demes. This allows us to obtain the distribution and the expectation of the coalescence times, and to deduce from them the distribution of the average pairwise differences and the evolution of F-st. Our results reflect the impact of the founder effect, which becomes stronger as the distance of the deme from the first deme increases. An increase in migration rate or growth rate generally leads to a decrease of the founder effect. F-st (i) increases during the beginning of the colonization, (ii) decreases when migration creates homogenization and (iii) increases again towards an equilibrium value. The distributions of pairwise coalescence times or differences between sequences show a peak corresponding to the colonization period. These results could help detect former colonization events in natural populations. (C) 1997 Academic Press.