Dogs, Wolves Not as Close as Assumed
A new genetic study suggests that dogs aren't as closely related to wolves as previously thought.
The research challenges the idea that humans started breeding dogs after the dawn of agriculture. According to the study, both dogs and wolves originated from an ancient ancestor between 9,000 and 34,000 years ago and that dogs were bred by early hunter-gatherers.
The study also shows that dogs are much more closely related to each other than any lineage of modern wolves.
Any overlap between wolves and dogs might be a result of interbreeding between the two species that may have occurred after domestication, according to the research authors.
"Dog domestication is more complex than we originally thought. In this analysis we didn't see clear evidence in favor of a multi-regional model, or a single origin from one of the living wolves that we sampled. It makes the field of dog domestication very intriguing going forward," said John Novembre, associate professor in the Department of Human Genetics at the University of Chicago and a senior author on the study,a ccording to a news release.
Where did Dogs Come From?
It is widely believed that wolf lineages from either of these regions; China, Middle-East or Europe were first domesticated. Therefore, scientists generated high-quality genome of gray wolves from Israel, China and Croatia for the study. The team also sequenced genome of two breeds of dogs; a basenji from Central Africa and a Dingo from Australia.
Note that both Central Africa and Australia are isolated from all modern wolf populations. Also, to round things up, researchers generated a genome of a golden jackal, which served as an "outgroup" and represented early divergence from both wolves and dogs.
The team then compared all these genomes along with an earlier sequenced genome of a boxer.
The experts anticipated finding at least one dog breed that would be genetically related to either one of the three wolf lineages. However, to their surprise, they found that both species were descendents of a common wolf-like ancestor.
"One possibility is there may have been other wolf lineages that these dogs diverged from that then went extinct," Novembre said in a news release. "So now when you ask which wolves are dogs most closely related to, it's none of these three because these are wolves that diverged in the recent past. It's something more ancient that isn't well represented by today's wolves."
The Starchy Diet
Previous research had suggested that domestication of dogs got a push from a set of genes that helped dogs cope with more starch in their diets.
The current study looked at additional genome of 12 breeds of dogs and found that most of them had amylase (AMY2B) genes. The gene was also present in wolves.
Elaine Ostrander, an investigator at the National Human Genome Research Institute told The Discovery News that the research answers some questions, but raises several others.
The study is published in the journal PLOS Genetics.