Coll.4 journal club: Phenotypic integration and covariation in a fly
This Friday, the 27th of January, we will discuss a paper by Haber and Dworkin from 2017 called "Disintegrating the fly: A mutational perspective on phenotypic integration and covariation"
Hope to see you there!
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.