Genomic study provides new clues to early canine history

good lookin dogs_blogAlthough they may share a common ancestor, dogs and wolves are not as closely related as previously thought.

New research from the University of Chicago suggests that domestic dogs are more closely related to each other, despite geographic location, than to wolves. The findings also point to a common ancestor for dogs and wolves somewhere between 9,000 and 34,000 years ago, according to a statement from the university.

The findings were published in PLoS Genetics yesterday.

Researchers attribute the closer relations within the dog genome as a result of interbreeding following domestication. It also turns the idea that early farms adopted easygoing wolves that later evolved into modern day man’s best friend on its head. Rather, researchers believe early dogs many have lived with hunter-gatherer groups and made the transition to living among agrarian societies later.

The findings are based on genomic analysis from a trio of gray wolves, each from an area where domestic dogs are believed to have originated – China, Croatia and Israel. They also sequenced the genomes of the modern day basenji, which traces its roots to central Africa, and the dingo, an Australian wild dog. Importantly, both of these breeds have been relatively isolated from wolf populations. A third previously published genome from a boxer also was analyzed. Finally, researchers sequenced the genome of the golden jackal, which is believed to have diverged earlier.

Their findings are intriguing – the three dog breeds were more related to each other than the wolves, and the wolves were more related to each other than the dog breeds. Researchers had expected each dog to be more closely linked to the wolf breed nearest its original geographic location, or the three dog breeds to be related to one wolf linage. The researchers also took gene flow into account, which muddle results.

“One possibility is there may have been other wolf lineages that these dogs diverged from that then went extinct,” said John Novembre, an associate professor at the University of Chicago and the study’s senior author, in a statement. “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.”

Differences in the amount of amylase (AMY2B) genes, which are related to starch digestion, also were found between dogs and wolves. They found that dog breeds typically associated with agricultural societies had more of these genes, while breeds such as Siberian huskies and dingoes, had fewer of these genes. Wolves also possessed some of these genes, which suggest that number of genes could have further increased after the divergence.

Read more about the study’s findings here.

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