PT  - JOURNAL ARTICLE
AU  - Gratten, J.
AU  - Wilson, A. J.
AU  - McRae, A. F.
AU  - Beraldi, D.
AU  - Visscher, P. M.
AU  - Pemberton, J. M.
AU  - Slate, J.
TI  - A Localized Negative Genetic Correlation Constrains Microevolution of Coat Color in Wild Sheep
AID  - 10.1126/science.1151182
DP  - 2008 Jan 18
TA  - Science
PG  - 318--320
VI  - 319
IP  - 5861
4099  - http://science.sciencemag.org/content/319/5861/318.short
4100  - http://science.sciencemag.org/content/319/5861/318.full
SO  - Science2008 Jan 18; 319
AB  - The evolutionary changes that occur over a small number of generations in natural populations often run counter to what is expected on the basis of the heritability of traits and the selective forces acting upon them. In Soay sheep, dark coat color is associated with large size, which is heritable and positively correlated with fitness, yet the frequency of dark sheep has decreased. This unexpected microevolutionary trend is explained by genetic linkage between the causal mutation underlying the color polymorphism and quantitative trait loci with antagonistic effects on size and fitness. As a consequence, homozygous dark sheep are large, but have reduced fitness relative to phenotypically indistinguishable dark heterozygotes and light sheep. This result demonstrates the importance of understanding the genetic basis of fitness variation when making predictions about the microevolutionary consequences of selection.