Reversal of response to artificial selection on body size in a wild passerine
Reversal of response to artificial selection on body size in a wild passerine
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野生雀形目动物对体型人工选择反应的逆转
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
B. Sæther
中科院分区：
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作者：
Thomas Kvalnes;T. Ringsby;H. Jensen;Ingerid J. Hagen;Bernt Rønning;H. Pärn;H. Holand;S. Engen;B. Sæther
数量遗传学中的一个普遍假设是存在一个中间表型，在平均环境中比极端表型具有更高的平均个体适应度。在这里，我们研究了野生鸟类种群中这种表型的进化性和存在，该实验为期11年，其中4年是对长和短跗骨长度（身体大小的代表）进行人工选择。该实验导致在施加的方向上的强选择。然而，人工选择被人工选择的父母后代的新兵产量减少所抵消。这导致了对极端性状值的弱自然选择。在表型和遗传水平上观察到对人工选择的显着反应，然后是对实验前手段的显着回报。在人工选择，每年观察到的表型反应密切遵循数量遗传理论的预测反应（ryears = 0.96，rcoholts = 0.56）。快速返回到实验前的手段是由三个相互作用的机制：选择一个中间表型，移民和重组之间的选择和筛选的个人。本研究的结果表明，表型的进化性和选择可能有利于野生种群的中间表型。
A general assumption in quantitative genetics is the existence of an intermediate phenotype with higher mean individual fitness in the average environment than more extreme phenotypes. Here, we investigate the evolvability and presence of such a phenotype in wild bird populations from an eleven‐year experiment with four years of artificial selection for long and short tarsus length, a proxy for body size. The experiment resulted in strong selection in the imposed directions. However, artificial selection was counteracted by reduced production of recruits in offspring of artificially selected parents. This resulted in weak natural selection against extreme trait values. Significant responses to artificial selection were observed at both the phenotypic and genetic level, followed by a significant return toward preexperimental means. During artificial selection, the annual observed phenotypic response closely followed the predicted response from quantitative genetic theory ( ryears = 0.96, rcohorts = 0.56). The rapid return to preexperimental means was induced by three interacting mechanisms: selection for an intermediate phenotype, immigration, and recombination between selected and unselected individuals. The results of this study demonstrates the evolvability of phenotypes and that selection may favor an intermediate phenotype in wild populations.