Thursday, February 05, 2009

The rise of the black wolf   posted by Razib @ 2/05/2009 01:34:00 PM

Molecular and Evolutionary History of Melanism in North American Gray Wolves:
Morphologic diversity within closely related species is an essential aspect of evolution and adaptation. Mutations in the Melanocortin 1 receptor (Mc1r) gene contribute to pigmentary diversity in natural populations of fish, birds, and many mammals. However, melanism in the gray wolf, Canis lupus, is caused by a different melanocortin pathway component, the K locus, that encodes a beta-defensin protein which acts as an alternative ligand for the Mc1r. We show that the melanistic K locus mutation in North American wolves derives from past hybridization with domestic dogs, has risen to high frequency in forested habitats, and exhibits a molecular signature of positive selection. The same mutation also causes melanism in the coyote, Canis latrans, and Italian gray wolves, and hence our results demonstrate how traits selected in domesticated species can influence the morphologic diversity of their wild relatives.

Also see ScienceDaily. The general dynamics should be relatively familiar. Here's the model in a figure: