Data from: Disintegrating the fly: a mutational perspective on phenotypic integration and covariation

The structure of environmentally induced phenotypic covariation can influence the effective strength and magnitude of natural selection. Yet our understanding of the factors that contribute to and influence the evolutionary lability of such covariation is poor. Most studies have either examined environmental variation without accounting for covariation, or examined phenotypic and genetic covariation without distinguishing the environmental component. In this study we examined the effect of mutational perturbations on different properties of environmental covariation, as well as mean shape. We use strains of Drosophila melanogaster bearing well-characterized mutations known to influence wing shape, as well as naturally-derived strains, all reared under carefully-controlled conditions and with the same genetic background. We find that mean shape changes more freely than the covariance structure, and that different properties of the covariance matrix change independently from each other. The perturbations affect matrix orientation more than they affect matrix eccentricity or total variance. Yet, mutational effects on matrix orientation do not cluster according to the developmental pathway that they target. These results suggest that it might be useful to consider a more general concept of ‘decanalization’, involving all aspects of variation and covariation.环境诱导的表型协变（phenotypic covariation）结构可影响自然选择的有效强度与作用幅度。然而，目前学界对这类协变的进化易变性的影响因素的认知仍较为匮乏。绝大多数现有研究要么仅考察环境变异却未考虑协变关系，要么仅分析表型与遗传协变却未区分其中的环境组分。本研究探究了突变扰动（mutational perturbations）对环境协变的不同属性以及平均翅形的影响。本研究使用两类黑腹果蝇（Drosophila melanogaster）品系：一类为携带经充分表征且已知可影响翅形的突变品系，另一类为自然衍生品系；所有品系均在严格可控的一致条件下饲养，且具备相同的遗传背景。研究结果显示，平均翅形的变化较协方差结构更为自由，且协方差矩阵的不同属性彼此独立地发生变化。相较于对矩阵偏心率与总方差的影响，突变扰动对矩阵取向的作用更为显著。然而，突变对矩阵取向的影响并未按照其靶向的发育通路进行聚类。上述结果提示，我们可引入更具普适性的“去渠化”（decanalization）概念，该概念涵盖变异与协变的所有维度。