Experimental evolution for generalists and specialists reveals multivariate genetic constraints on thermal reaction norms
Experimental evolution for generalists and specialists reveals multivariate genetic constraints on thermal reaction norms
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DOI：
10.1111/jeb.12452
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发表时间：
2014-09-01
影响因子：
2.1
通讯作者：
Blanckenhorn, W. U.
中科院分区：
文献类型：
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作者：
Berger, D.;Walters, R. J.;Blanckenhorn, W. U.
理论预测出现通才在可变的环境和拮抗多效性有利于专家在恒定的环境，但经验数据很少支持这样的通才专家权衡。我们选择的通才和专家粪蝇脓毒症斑点（双翅目：Sepsidae）的条件下，我们预测将揭示拮抗多效性和多变量权衡的基础上的热反应规范的少年发展。我们使用四种处理方法进行了重复的实验室进化：在热（31摄氏度）或冷（15摄氏度）温度下的适应，或者在这些温度之间波动的制度下，无论是在一代人内还是在两代人之间。20代后，我们评估了三个相关的生活史性状的热反应规范的父母的影响和遗传反应：大小在成熟，少年生长速度和少年生存。我们发现的证据拮抗多效性的表现在炎热和寒冷的温度，和温度介导的权衡之间的少年生存和大小在成熟，这表明权衡与环境耐受性可以出现通过加强进化的妥协之间的遗传相关的性状。然而，尽管这种拮抗性多效性，我们发现没有支持的进化增加的耐热性的宽度，在牺牲降低最大性能，这表明低遗传方差的通才专家的尺寸。
Theory predicts the emergence of generalists in variable environments and antagonistic pleiotropy to favour specialists in constant environments, but empirical data seldom support such generalist-specialist trade-offs. We selected for generalists and specialists in the dung fly Sepsis punctum (Diptera: Sepsidae) under conditions that we predicted would reveal antagonistic pleiotropy and multivariate trade-offs underlying thermal reaction norms for juvenile development. We performed replicated laboratory evolution using four treatments: adaptation at a hot (31 degrees C) or a cold (15 degrees C) temperature, or under regimes fluctuating between these temperatures, either within or between generations. After 20 generations, we assessed parental effects and genetic responses of thermal reaction norms for three correlated life-history traits: size at maturity, juvenile growth rate and juvenile survival. We find evidence for antagonistic pleiotropy for performance at hot and cold temperatures, and a temperature-mediated trade-off between juvenile survival and size at maturity, suggesting that trade-offs associated with environmental tolerance can arise via intensified evolutionary compromises between genetically correlated traits. However, despite this antagonistic pleiotropy, we found no support for the evolution of increased thermal tolerance breadth at the expense of reduced maximal performance, suggesting low genetic variance in the generalist-specialist dimension.