Evolution of Genetic Covariance Structure ^__

Genetic covariance structure is a central element for describing multivariate evolutionary change generated by natural selection and genetic drift. The is frequently summarized using the so-called G-matrix.

We have developed software for analyzing changes in genetic covariance structure using a hierarchical approach developed by Bernard Flury (see Software).

We have applied these techniques to looking at the evolution of scalation patterns in garter snakes

(See Phillips & Arnold 1999 and Arnold and Phillips 1999).

And to the effects of drift on wing shape genetics in Drosophila.

The average influence of drift leads to proportionality across all traits as expected by theory (outer ovals represent the covariance pattern in the outbred population and the inner ovals represent the average covariance over a large number of inbred popluations).

For any single population, however, the pattern of covariance can be widely divergent.

(Phillips, Whitlock, and Folwer. 2001. Genetics, in press)