Washington, February 6 (ANI): An international group of researchers have unravelled the mystery as to why nearly half of North American wolves have black coats, while European wolves are overwhelmingly grey or white.
The team - comprising biologists and molecular geneticists from Stanford University, UCLA, Sweden, Canada and Italy - say that the black coats are the result of historical mating between black dogs and wild grey wolves.
The National Science Foundation-funded study, appearing in the online edition of the journal Science, involved molecular genetic techniques to analyse DNA sequences from 150 wolves in Yellowstone National Park, which covers parts of Wyoming, Montana and Idaho.
The researcher revealed that about half of the wolves studied were black.
They observed that a novel mutated variant of a gene in dogs, known as the K locus, was responsible for black coat colour, and was transferred to wolves through mating.
The researchers admitted that it was yet to be determined as to when the black coat colour was transferred from dogs to wolves.
According to them, it could not have occurred recently, as the black coat could not have spread as widely as it has throughout North America in just a few hundred years.
The team reckon that the transfer might have taken place sometime before the arrival of Europeans to North America, and involved dogs that were here with Native Americans.
"This is the first example where a gene mutation originated in a domesticated species, was transferred to and became very common in a closely related wild species," said Robert Wayne, a UCLA professor of ecology and evolutionary biology and co-author of the Science paper.
"Although genes that evolve under domestication may be transferred to wild species, they generally do not proliferate in the wild because the natural context is so different from that under domestication.
"No one would have guessed that the common black coat colour in North American wolves came from dogs - there is no precedent for it. Moreover, for whatever reason, the transfer of the black coat-colour gene from dogs to wolves and its success in the wild occurred uniquely in North America.
"Most mutations we see in dogs have been selected by humans, and we intuitively think they are unique to dogs. We don't think of short-legged wolves like dachshunds or wild wolves that look like Dalmatians. The surprise of this study is that black wolves have their black coat coloration as a gift from dogs. The products of artificial selection had added substantially to the genetic legacy of a wild species," Wayne added.
The researchers say that their findings have implications beyond dogs and wolves.
"The underlying assumption is that genes from one species will be contained and not enter another species on a massive scale; this may not be true. There may be implications for genetically modified organisms," Wayne said.
The researchers believe that their work will help to refine concepts relevant to both genetics and conservation biology with respect to understanding how different traits arise during evolution, and how biological diversity can be nurtured and maintained. (ANI)