School of Biological Sciences, The University of Queensland, Brisbane, 4072, Australia.
Evolution. 2010 Jul;64(7):1899-911. doi: 10.1111/j.1558-5646.2010.00968.x. Epub 2010 Feb 9.
Genetic covariation among multiple traits will bias the direction of evolution. Although a trait's phenotypic context is crucial for understanding evolutionary constraints, the evolutionary potential of one (focal) trait, rather than the whole phenotype, is often of interest. The extent to which a focal trait can evolve independently depends on how much of the genetic variance in that trait is unique. Here, we present a hypothesis-testing framework for estimating the genetic variance in a focal trait that is independent of variance in other traits. We illustrate our analytical approach using two Drosophila bunnanda trait sets: a contact pheromone system comprised of cuticular hydrocarbons (CHCs), and wing shape, characterized by relative warps of vein position coordinates. Only 9% of the additive genetic variation in CHCs was trait specific, suggesting individual traits are unlikely to evolve independently. In contrast, most (72%) of the additive genetic variance in wing shape was trait specific, suggesting relative warp representations of wing shape could evolve independently. The identification of genetic variance in focal traits that is independent of other traits provides a way of studying the evolvability of individual traits within the broader context of the multivariate phenotype.
多个性状之间的遗传协变会影响进化的方向。虽然性状的表型背景对于理解进化约束至关重要，但人们通常更感兴趣的是一个（焦点）性状的进化潜力，而不是整个表型。焦点性状能够独立进化的程度取决于该性状中独特遗传方差的多少。在这里，我们提出了一个用于估计焦点性状中与其他性状方差无关的遗传方差的假设检验框架。我们使用两个 Drosophila bunnanda 性状集来说明我们的分析方法：一个由表皮烃（CHCs）组成的接触信息素系统，以及以脉位坐标的相对扭曲为特征的翅膀形状。CHCs 的加性遗传变异中只有 9%是特定于性状的，这表明单个性状不太可能独立进化。相比之下，翅膀形状的加性遗传方差中大多数（72%）是特定于性状的，这表明翅膀形状的相对扭曲表示可以独立进化。鉴定与其他性状无关的焦点性状的遗传方差为在更广泛的多变量表型背景下研究单个性状的可进化性提供了一种方法。
