Data from: The evolution of phenotypic integration: How directional selection reshapes covariation in mice

‭Variation is the basis for evolution, and understanding how variation can evolve is a central question in biology. In complex phenotypes, covariation plays an even more important role, as genetic associations between traits can bias and alter evolutionary change. Covariation can be shaped by complex interactions between loci, and this genetic architecture can also change during evolution. In this article, we analyzed mouse lines experimentally selected for changes in size to address the question of how multivariate covariation changes under directional selection, as well as to identify the consequences of these changes to evolution. Selected lines showed a clear restructuring of covariation in their cranium and, instead of depleting their size variation, these lines increased their magnitude of integration and the proportion of variation associated with the direction of selection. This result is compatible with recent theoretical works on the evolution of covariation that take the complexities of genetic architecture into account. This result also contradicts the traditional view of the effects of selection on available covariation and suggests a much more complex view of how populations respond to selection.变异是演化的核心基础，探究变异自身的演化规律是生物学领域的关键议题。在复杂表型中，协变异（covariation）的作用更为凸显：不同性状间的遗传关联可偏倚并改变演化路径。协变异可由基因座间的复杂互作塑造，且这类遗传架构在演化进程中亦会发生改变。本研究针对经实验选育以改变体型的小鼠品系开展分析，旨在解答定向选择下多变量协变异的演化模式，并探明此类协变异改变对演化产生的后续影响。经选育的小鼠品系其颅骨的协变异结构出现了显著重构；不仅未消减体型相关变异，反而提升了性状整合程度，且与定向选择方向相关的变异占比亦有所升高。该结果与近期纳入遗传架构复杂性的协变异演化理论研究相符，同时也颠覆了传统认知中选择对可利用协变异的影响范式，表明种群响应选择的机制远比此前认知更为复杂。