Contrasting patterns of body shape and neutral genetic divergence in marine and lake populations of threespine sticklebacks
Contrasting patterns of body shape and neutral genetic divergence in marine and lake populations of threespine sticklebacks
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DOI：
10.1111/j.1420-9101.2006.01182.x
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发表时间：
2006-11-01
影响因子：
2.1
通讯作者：
Merila, J.
中科院分区：
文献类型：
--
作者：
Leinonen, T.;Cano, J. M.;Merila, J.
中性标记和数量性状差异的比较可以为研究自然选择和中性遗传漂变在群体分化中的相对作用提供重要的见解。研究了芬诺斯坎德三刺棘鱼（Gasterosteus aculeatus）种群的表型和遗传分化，发现海水和淡水生境之间的分化程度最高。在生境内，不同淡水居群的形态差异最大。种群间的表型和中性遗传距离呈显著正相关，表明遗传漂变可能对生境间的形态分化起到了促进作用。另一方面，表型分化程度（P-ST）明显超过了F-ST设定的中性预期，表明自然选择比遗传漂变更能解释所观察到的分化。然而，通过栖息地进行的单独P-ST/F-ST比较显示，湖泊和海洋种群之间，甚至海洋种群之间的体型差异可能受到自然选择的强烈影响。另一方面，遗传漂变在湖泊种群分化中起着重要作用。
Comparisons of neutral marker and quantitative trait divergence can provide important insights into the relative roles of natural selection and neutral genetic drift in population differentiation. We investigated phenotypic and genetic differentiation among Fennoscandian threespine stickleback (Gasterosteus aculeatus) populations, and found that the highest degree of differentiation occurred between sea and freshwater habitats. Within habitats, morphological divergence was highest among the different freshwater populations. Pairwise phenotypic and neutral genetic distances among populations were positively correlated, suggesting that genetic drift may have contributed to the morphological differentiation among habitats. On the other hand, the degree of phenotypic differentiation (P-ST) clearly surpassed the neutral expectation set by F-ST, suggesting a predominant role for natural selection over genetic drift as an explanation for the observed differentiation. However, separate P-ST/F-ST comparisons by habitats revealed that body shape divergence between lake and marine populations, and even among marine populations, can be strongly influenced by natural selection. On the other hand, genetic drift can play an important role in the differentiation among lake populations.