VARIATION IN PLEIOTROPY AND THE MUTATIONAL UNDERPINNINGS OF THE G-MATRIX
Article first published online: 8 MAY 2007
Volume 60, Issue 12, pages 2655–2660, December 2006
How to Cite
Estes, S. and Phillips, P. C. (2006), VARIATION IN PLEIOTROPY AND THE MUTATIONAL UNDERPINNINGS OF THE G-MATRIX. Evolution, 60: 2655–2660. doi: 10.1111/j.0014-3820.2006.tb01897.x
- Issue published online: 8 MAY 2007
- Article first published online: 8 MAY 2007
- Received November 23, 2005. Accepted September 12, 2006.
- Mismatch repair;
- mutation accumulation;
- mutational covariance;
- population size;
Abstract The pattern and extent of pleiotropic gene action can contribute substantially to the internal structure and shape of the additive genetic variance-covariance matrix (G)–a key determinant of evolutionary trajectories. We use data from our study (Estes et al. 2004) on the univariate effects of mutation in a mismatch-repair-defective strain, msh-2, of Caenorhabditis elegans to address the impact of increasing levels of selection on the magnitude and pattern of genetic covariance due to new mutations. Mutational covariances between three life-history traits are shown to exhibit a weak pattern of decline with increasing population size (increasing selection), while the orientation of mutational matrices remains reasonably constant. This suggests that mutations with smaller effects on fitness may tend to be slightly more confined in their influence than large-effect mutations (i.e., small-effect mutations reduce the magnitude of covariation between characters), but do not change the direction of this covariation.