Antagonistic selection factors induce a continuous population divergence in a polymorphism
Antagonistic selection factors induce a continuous population divergence in a polymorphism
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拮抗选择因素导致多态性中的连续群体分化
DOI：
10.1038/hdy.2013.117
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发表时间：
2014
期刊：
影响因子：
3.8
通讯作者：
N. Nagata and M. Kawata
中科院分区：
文献类型：
--
作者：
Takahashi;Y.;N. Nagata and M. Kawata
了解选择因素和随机因素在适应性状群体分化中的相对重要性是进化生物学的一个经典课题。然而，当两个或多个不同的选择因子同时作用于单个基因座时，很难分离这些因素并检测选择的影响。在塞内加尔豆娘Ischnura senegalensis中，雌性豆娘表现出颜色二态性和形态频率的地理变化。通过比较颜色位点和中性位点的差异，评价了选择和随机因素在种群形态频率差异中的作用。中性位点和颜色位点的群体两两fst比较未发现任何影响颜色位点的随机因素。虽然在所有种群中比较种群的颜色差异和中性位点只发现了发散选择，但在考虑种群间地理距离时，我们发现了两种拮抗选择因素，即平衡选择和发散选择。我们的研究结果表明，两个拮抗选择因素的组合，而不是随机因素，建立了该系统中形态频率的地理梯度。
Understanding the relative importance of selection and stochastic factors in population divergence of adaptive traits is a classical topic in evolutionary biology. However, it is difficult to separate these factors and detect the effects of selection when two or more contrasting selective factors are simultaneously acting on a single locus. In the damselfly Ischnura senegalensis, females exhibit color dimorphism and morph frequencies change geographically. We here evaluated the role of selection and stochastic factors in population divergence of morph frequencies by comparing the divergences in color locus and neutral loci. Comparisons between population pairwise F ST for neutral loci and for the color locus did not detect any stochastic factors affecting color locus. Although comparison between population divergence in color and neutral loci using all populations detected only divergent selection, we detected two antagonistic selective factors acting on the color locus, that is, balancing and divergent selection, when considering geographical distance between populations. Our results suggest that a combination of two antagonistic selective factors, rather than stochastic factors, establishes the geographic cline in morph frequency in this system.