JOINT ALLELIC EFFECTS ON FITNESS AND METRIC TRAITS
Article first published online: 29 NOV 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 67, Issue 4, pages 1131–1142, April 2013
How to Cite
McGuigan, K. and Blows, M. W. (2013), JOINT ALLELIC EFFECTS ON FITNESS AND METRIC TRAITS. Evolution, 67: 1131–1142. doi: 10.1111/j.1558-5646.2012.01833.x
- Issue published online: 3 APR 2013
- Article first published online: 29 NOV 2012
- Accepted manuscript online: 29 OCT 2012 01:35PM EST
- Received April 19, 2012 Accepted October 11, 2012 Data Archived: Dryad doi:10.5061/dryad.4pd30
- Drosophila serrata;
- sexual selection;
Theoretical explanations of empirically observed standing genetic variation, mutation, and selection suggest that many alleles must jointly affect fitness and metric traits. However, there are few direct demonstrations of the nature and extent of these pleiotropic associations. We implemented a mutation accumulation (MA) divergence experimental design in Drosophila serrata to segregate genetic variants for fitness and metric traits. By exploiting naturally occurring MA line extinctions as a measure of line-level total fitness, manipulating sexual selection, and measuring productivity we were able to demonstrate genetic covariance between fitness and standard metric traits, wing size, and shape. Larger size was associated with lower total fitness and male sexual fitness, but higher productivity. Multivariate wing shape traits, capturing major axes of wing shape variation among MA lines, evolved only in the absence of sexual selection, and to the greatest extent in lines that went extinct, indicating that mutations contributing wing shape variation also typically had deleterious effects on both total fitness and male sexual fitness. This pleiotropic covariance of metric traits with fitness will drive their evolution, and generate the appearance of selection on the metric traits even in the absence of a direct contribution to fitness.