Genetic change for earlier migration timing in a pink salmon population
Genetic change for earlier migration timing in a pink salmon population
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DOI：
10.1098/rspb.2012.1158
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发表时间：
2012-09-22
影响因子：
4.7
通讯作者：
Tallmon, David A.
中科院分区：
文献类型：
--
作者：
Kovach, Ryan P.;Gharrett, Anthony J.;Tallmon, David A.
为了预测气候变化将如何影响种群，有必要了解允许种群在新环境条件下持续存在的机制，特别是微进化和表型可塑性。尽管气候引起种群表型变化的证据广泛存在，但证明这些表型变化是由微进化引起的证据却极为罕见。在这项研究中，我们使用32年的遗传数据（17个完整的世代）来确定是否有遗传变化向早期迁移时间在粉红色鲑鱼群体中显示表型变化；平均迁移时间比40年前提前了近两周。实验遗传数据支持这一假设，即早期迁移时间存在定向选择，导致晚迁移表型大幅减少（从总丰度的30%以上降至10%以下）。从1983年到2011年，晚迁移时间遗传标记的频率显著降低了三倍以上，但其他中性位点的等位基因频率变化很小。这些结果表明，该种群在早期迁移时间方面存在快速的微进化。然而，从1993年到2009年，昼夜节律基因没有显示出任何选择性变化的证据。
To predict how climate change will influence populations, it is necessary to understand the mechanisms, particularly microevolution and phenotypic plasticity, that allow populations to persist in novel environmental conditions. Although evidence for climate-induced phenotypic change in populations is widespread, evidence documenting that these phenotypic changes are due to microevolution is exceedingly rare. In this study, we use 32 years of genetic data (17 complete generations) to determine whether there has been a genetic change towards earlier migration timing in a population of pink salmon that shows phenotypic change; average migration time occurs nearly two weeks earlier than it did 40 years ago. Experimental genetic data support the hypothesis that there has been directional selection for earlier migration timing, resulting in a substantial decrease in the late-migrating phenotype (from more than 30% to less than 10% of the total abundance). From 1983 to 2011, there was a significant decrease-over threefold-in the frequency of a genetic marker for late-migration timing, but there were minimal changes in allele frequencies at other neutral loci. These results demonstrate that there has been rapid microevolution for earlier migration timing in this population. Circadian rhythm genes, however, did not show any evidence for selective changes from 1993 to 2009.