Mutation rates as life history traits

Mutation is the source of genetic variation, and the rate at which mutations occur influences a wide range of evolutionary phenomena. Understanding the factors that shape the mutation rate has hence been a long-standing quest in evolutionary biology. Most mutations with phenotypic effects are deleterious.

The prevailing hypothesis therefore suggests that the germline mutation rate is simply pushed back to a minimum set by the power struggle between selection and drift.

Accumulating data on both the germline and the somatic mutation rate has nevertheless started to challenge this view, and several lines of evidence point to the fact that keeping mutation rates low is energetically costly.

The emerging view therefore suggests that mutation rates should be considered life history traits, where investments in driving them down trade-off with other activities.

In this proposal, I outline a project designed to comprehensively test if mutation rates bear the characteristics of life history traits.

Harnessing several Drosophila melanogaster model systems, I will (i) use quantitative genetics to estimate the evolutionary potential of these traits, (ii) employ experimental evolution to assess if selection on the life history causes indirect selection on mutation rates, and (iii) test for a plastic response in mutation rates when the environment favors changes in investment across the life history.

This project will provide novel insight into a topic of broad evolutionary significance.