Reinhard Bürger

Department of Mathematics, University of Vienna, Austria

Epistasis, mutational architecture, and the response to selection of complex traits

[When and where]

The evolutionary dynamics of complex traits is constrained by levels of genetic variation as well as genetic correlations among traits. Because the ultimate source of genetic variation is mutation, the distribution of mutations entering populations profoundly affects standing variation and genetic correlations. The talk will focus on results from a recent study [1] that was designed to investigate how natural selection and gene interactions (i.e., epistasis) shape the evolution of mutational processes affecting complex traits, and thus affect the response to selection. We found that the presence of epistasis allows natural selection to mold the distribution of mutations, such that the matrix of mutational effects aligns with that determining the selection surface. Consequently, novel mutations tend to be more compatible with the current forces of selection acting on the population. Counterintuitively, we found that smaller populations can sometimes harbor higher genetic variances than corresponding larger ones. These results suggest that in many cases mutational effects should be seen as an outcome of natural selection rather than as an unbiased source of genetic variation that is independent of other evolutionary processes. Importantly, the resulting G-matrix is then determined both the evolving matrix of mutational effects and by the selective forces.

[1] Jones AG, Bürger R, Arnold J: Epistasis and natural selection shape the mutational architecture of complex traits. Nature Communications 5:3709 (2014)

reinhard.buerger[AT]univie.ac.at

Invited talk Mini-symposium 5

Updated May 13, 2015, by Minus