What is in this article?:
- Farming shaped dog evolution, study finds
- Parting company
- New findings supply the missing piece to the puzzle of when ancient dogs expanded from Southeast Asia.
To calculate when the modern European and Southeast Asian dogs diverged, the researchers calculated the mutation rate of genetic markers on the Y chromosome in a sample of 100 Australian dingoes, a dog population known to have appeared about 4,200 years ago. Knowing the rate at which these genetic mutations occur, the researchers were able to backtrack through history and estimate the point when dogs of Eurasia and Southeast Asia parted company as being roughly 7,000 years ago.
“So, in a sense, both of the original hypotheses are true: Dogs did originate in Europe and the Middle East, but modern dogs trace their ancestry most recently to the East and specifically Southeast Asia,” Sacks said.
He noted that a study, led by evolutionary geneticist Erik Axelsson from Uppsala University in Sweden and published in the January issue of the journal Nature, suggests a distinction between dogs and wolves can be seen in their ability to digest starch, strongly suggesting an evolutionary adaptation to human farmers.
“Both studies fit together nicely, although our research teams differ on when we suspect modern dogs developed the ability to digest starch,” Sacks said. “The other group suggested that diet-related change happened at the outset of dog origins, at which time humans were still hunter-gatherers.”
“In contrast, we hypothesize that the starch adaptation occurred much later in Southeast Asia, once agriculture — rice farming in this case — had become the major mode of subsistence for humans,” he said.
Sacks said that the UC Davis-led study also shines light on the origin of dingoes, the wild dogs of Australia.
Data from the study suggest that New Guinea singing dogs and Australian dingoes reflect a dispersal of dogs, possibly from Taiwan, that was independent of the movement of dogs throughout the islands of Southeast Asia. The island dogs appear to have originated in mainland Southeast Asia, rather than Taiwan, he said.
The possibility of Taiwan being the origin of an independent migration for these dogs Down Under is intriguing but will require further research to confirm, Sacks said.
Other researchers on this study were: Sarah Brown and Niels Pederson of the UC Davis School of Veterinary Medicine; Jui-Te Wu of National Chiayi University, Taiwan; Danielle Stephens of Helix Molecular Solutions in Crawley, Australia; and Oliver Berry, Commonwealth Scientific and Industrial Research Organization, Australia.
Funding for the study was provided by the Center for Global, International and Regional Studies, UC Davis’ Veterinary Genetics Laboratory and UC Davis’ Center for Companion Animal Health.