What do genetic background effects and cryptic genetic variation tell us about the genotype-phenotype map?

Abstract: Considerable conceptual, theoretical and empirical work has been done exploring how genetic information is used by an organism to mediate the expression of phenotypes. More precisely, how phenotypic variation maps onto genotype or genotypic variation. While the representations of both intermediate (gene expression, cellular, tissue and developmental) and adult phenotypes are often suitably complex, the abstractions for genotype usually only consider the consequences of the focal genetic change (i.e. a particular mutation). However, just as external environmental influences (rearing temperature, food, density) during organismal development modulate genetic effects and thus phenotypic outcomes, so do the interactions between genetic background and the focal mutations. In this talk I will discuss work in our lab that examines the causes and consequences of genetic background effects, with respect to how it changes the perspective on the genotype-phenotype map, and also how it can contribute to evolutionary dynamics. Furthermore, I will discuss our recent work to understand the genetic and genomic basis of genetic assimilation for the classic crossveinless system of Drosophila melanogaster first developed by Waddington.