THE EVOLUTION OF TRADE‐OFFS: TESTING PREDICTIONS ON RESPONSE TO SELECTION AND ENVIRONMENTAL VARIATION
THE EVOLUTION OF TRADE‐OFFS: TESTING PREDICTIONS ON RESPONSE TO SELECTION AND ENVIRONMENTAL VARIATION
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DOI：
10.1111/j.0014-3820.2002.tb00851.x
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发表时间：
2002-01
期刊：
影响因子：
3.3
通讯作者：
D. Roff;S. Mostowy;D. Fairbairn
中科院分区：
文献类型：
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作者：
D. Roff;S. Mostowy;D. Fairbairn
表型权衡的概念是进化理论的核心要素。一般来说，表型模型假设一个固定的权衡函数，而定量遗传理论预测，权衡函数将作为选择的结果而改变。对于线性权衡函数，选择将很容易改变截距，但必须相对较强才能改变斜率。我们通过检验四个不同沙蟋蟀种群的繁殖力和飞行能力之间的权衡来验证这些预测，以背纵向肌肉质量来衡量。最近从野外获得了三个种群，第四个种群已经在实验室里待了19年。我们假设实验室种群与三个野生种群相比很可能经历了更多不同的选择，因此在斜率和截距方面应该与这些种群不同。由于地理选择的差异，我们预测四个种群之间的截距存在普遍差异。我们进一步验证了这一截距将与巨翼虫比例相关的假设，并且这种关系本身将随着若虫期和成虫期所经历的环境条件而变化。在表型权衡中观察到的变异与定量遗传模型的预测一致。这些结果指出了将权衡建模为动态关系而不是静态关系的重要性。我们讨论了表型模型如何纳入这种变异。繁殖力和背纵向肌肉质量之间的表型权衡在一定程度上是由体型的变化决定的，这说明了考虑权衡是多因素的必要性，而不是简单的二元关系。
Abstract The concept of phenotypic trade‐offs is a central element in evolutionary theory. In general, phenotypic models assume a fixed trade‐off function, whereas quantitative genetic theory predicts that the trade‐off function will change as a result of selection. For a linear trade‐off function selection will readily change the intercept but will have to be relatively stronger to change the slope. We test these predictions by examining the trade‐off between fecundity and flight capability, as measured by dorso‐longitudinal muscle mass, in four different populations of the sand cricket, Gryllus firmus. Three populations were recently derived from the wild, and the fourth had been in the laboratory for 19 years. We hypothesized that the laboratory population had most likely undergone more and different selection from the three wild populations and therefore should differ from these in respect to both slope and intercept. Because of geographic variation in selection, we predicted a general difference in intercept among the four populations. We further tested the hypothesis that this intercept will be correlated with proportion macropterous and that this relationship will itself vary with environmental conditions experienced during both the nymphal and adult period. Observed variation in the phenotypic trade‐off was consistent with the predictions of the quantitative genetic model. These results point to the importance of modeling trade‐offs as dynamic rather than static relationships. We discuss how phenotypic models can incorporate such variation. The phenotypic trade‐off between fecundity and dorso‐longitudinal muscle mass is determined in part by variation in body size, illustrating the necessity of considering trade‐offs to be multifactorial rather than simply bivariate relationships.