Trade-offs are fundamental to evolutionary outcomes and play a central role in eco-evolutionary theory. They are often examined by experimentally selecting on one life-history trait and looking for negative correlations in other traits. For example, populations of the moth Plodia interpunctella selected to resist viral infection show a life-history cost with longer development times. However, we rarely examine whether the detection of such negative genetic correlations depends on the trait on which we select. Here we examine a well-characterised negative genotypic trade-off between development time and resistance to viral infection in the moth Plodia interpunctella and test whether selection on a phenotype known to be a cost of resistance (longer development time) leads to the predicted correlated increase in resistance. If there is tight pleiotropic relationship between genes that determine development time and resistance underpinning this trade-off, we might expect increased resistance when we select on longer development time. However, we show that selecting for longer development time in this system selects for reduced resistance when compared to selection for shorter development time. This shows how phenotypes typically characterised by a trade-off can deviate from that trade-off relationship, and suggests little genetic linkage between the genes governing viral resistance and those that determine response to selection on the key life-history trait. Our results are important for both selection strategies in applied biological systems and for evolutionary modelling of host-parasite interactions.

中文翻译：

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选择的目标很重要：在选择发育时间时，没有发现既定的抗性-发育时间负遗传权衡


权衡是进化结果的基础，在生态进化理论中发挥着核心作用。通常通过实验选择一种生活史特征并寻找其他特征的负相关性来检查它们。例如，选择抵抗病毒感染的螟蛾种群表现出生命史成本和较长的发育时间。然而，我们很少检查这种负遗传相关性的检测是否取决于我们选择的性状。在这里，我们研究了印度谷蛾（Plodia interpunctella）发育时间和对病毒感染的抗性之间的良好表征的负基因型权衡，并测试对已知作为抗性成本（更长的发育时间）的表型的选择是否会导致预测的相关增加在抵抗中。如果决定发育时间的基因与支撑这种权衡的抗性之间存在紧密的多效性关系，那么当我们选择较长的发育时间时，我们可能会预期抗性会增加。然而，我们表明，与选择较短的开发时间相比，在该系统中选择较长的开发时间会减少阻力。这表明通常以权衡为特征的表型如何偏离这种权衡关系，并表明控制病毒抗性的基因与决定对关键生活史性状选择反应的基因之间几乎没有遗传联系。我们的结果对于应用生物系统中的选择策略和宿主-寄生虫相互作用的进化模型都很重要。