No evidence that warmer temperatures are associated with selection for smaller body sizes
No evidence that warmer temperatures are associated with selection for smaller body sizes
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没有证据表明较高的温度与较小体型的选择有关
DOI：
10.1098/rspb.2019.1332
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Kruuk, Loeske E.
中科院分区：
文献类型：
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作者：
Siepielski, Adam M.;Morrissey, Michael B.;Carlson, Stephanie M.;Francis, Clinton D.;Kingsolver, Joel G.;Whitney, Kenneth D.;Kruuk, Loeske E.
近几十年来，动物体型的缩小通常被解释为对气候变暖的适应性进化反应。然而，为了使体型的缩小反映出适应性进化，种群内体型的定向选择必须是负的，或者在已经是负的地方，随着温度的升高而变得更加负。为了验证这一假设，我们对39项纵向研究中野生种群体型方向选择的年度估计与年平均温度之间的关系进行了传统和系统发育荟萃分析。我们没有发现证据表明温暖的环境与小体型的选择有关。相反，自然选择始终倾向于体型较大的个体，并且不受温度的影响。这些模式在变温动物和恒温动物中是相似的。一项使用年份而不是温度的分析显示了类似的模式，表明没有证据表明选择随着时间的推移而改变，并且还表明缺乏与年温度的关联并不是选择错误的时间窗口来汇总温度数据的人工产物。尽管体型的表型趋势将由遗传和环境因素共同驱动，但我们的研究结果表明，几乎没有证据表明，体型下降的必要成分——负方向选择——被认为是对不断变化的选择压力的适应性进化反应。
Reductions in animal body size over recent decades are often interpreted as an adaptive evolutionary response to climate warming. However, for reductions in size to reflect adaptive evolution, directional selection on body size within populations must have become negative, or where already negative, to have become more so, as temperatures increased. To test this hypothesis, we performed traditional and phylogenetic meta-analyses of the association between annual estimates of directional selection on body size from wild populations and annual mean temperatures from 39 longitudinal studies. We found no evidence that warmer environments were associated with selection for smaller size. Instead, selection consistently favoured larger individuals, and was invariant to temperature. These patterns were similar in ectotherms and endotherms. An analysis using year rather than temperature revealed similar patterns, suggesting no evidence that selection has changed over time, and also indicating that the lack of association with annual temperature was not an artefact of choosing an erroneous time window for aggregating the temperature data. Although phenotypic trends in size will be driven by a combination of genetic and environmental factors, our results suggest little evidence for a necessary ingredient—negative directional selection—for declines in body size to be considered an adaptive evolutionary response to changing selection pressures.