These "dalliances" apparently occurred 10,000 - 15,000 years ago when people (and their dogs) first crossed the Bering Land Bridge from Asia.
What is particularly interesting is how the melanism gene has persisted only in the forest-dwellers and not in the tundra wolves, perhaps because the darker color has provided additional camouflage in the shady forest environs. Others suggest that that the trait is associated with better immune systems (strangely, at least one of the allele sets involved in melanism belongs to a family of genes that is involved in fighting off infections; see comments for more discussion). Of course, both camouflage and immune factors could be involved.
Click the post title above for a nice summary from Wired.com.
These findings were originally published in the 5 February 2009 is issue of the journal Science. Here's the abstract.
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2 comments:
Great article Dr. Carpenter. Do you know specifically which human genes the article is referencing?
According to the abstract for the Science paper (which I have now linked to in the post above) the gene is the "K locus" and encodes for a beta-defensin protein. The defensins form a family of antibiotic and cytotoxic peptides made by neutrophils. There seems to be controversy here though, as some now maintain that beta defensin is involved with melanin production only and not with any immune function. (See preview.tinyurl.com/kwloro.) Science in action!
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