Thursday, December 17, 2015

New twist in tale of dogs' origins

Date:
December 16, 2015
Source:
KTH The Royal Institute of Technology
Summary:
The origin of dogs has inspired a lingering controversy in academia. Where and when did dogs first split off from wolves? Now a top-dog researcher hopes his latest research will finally settle the matter.

This study provides strong evidence that the dog originated in South East Asia, which confirms earlier studies of Mitochondrial DNA. (Stock image)
Credit: © Lunja / Fotolia
 
The origin of dogs has inspired a lingering controversy in academia. Where and when did dogs first split off from wolves? One of the top dogs in this dispute, population genetics expert Peter Savolainen of Sweden's KTH Royal Institute of Technology, isn't about to roll over. He hopes his latest research will finally settle the matter.

Some researchers say canines first split off from wolves in the Middle East; others say it happened in Europe. But Savolainen has long held that dogs originated in South East Asia alone, and he says his team has compiled new evidence that confirms his earlier findings.

The study concludes that the split with wolves occurred about 33,000 years ago.

Savolainen's earlier studies were based on analysis of mitochondrial DNA. But recently other researchers have used data from nuclear DNA to refute those findings, arguing that dogs originated in the Middle East, Central Asia or Europe.

But apparently, those researchers were thrown off the scent, according to Savolainen. The data they relied on did not include samples from South East Asia, he says. So if, as Savolainen says, dogs did indeed come from South East Asia, these studies would not have been able to detect it.

"Which is why we analysed the entire nuclear genome of a global sample collection from 46 dogs, which includes samples from southern China and South East Asia," he says. "We then found out that dogs from South East Asia stand out from all other dog populations, because they have the highest genetic diversity and are genetically closest to the wolf."

Savolainen says this provides strong evidence that the dog originated in South East Asia, which confirms his earlier studies of Mitochondrial DNA. "We also found that the global dog population is based on two important events: the dog and wolf populations first began to split off about 33,000 years ago in South East Asia. The global spread of dogs followed about 18,000 years later.

He says one explanation for the split between dogs and wolves 33,000 years ago could be that the wolf population became divided and the south Chinese wolf developed into dogs. In that case, it is possible the global spread of dogs out of South East Asia is associated with domestication. "The dog's story thus appears to have begun 33,000 years ago, but the exact path to the fully-domesticated dogs that spread throughout the world 15,000 years ago is not yet clear."

Story Source:
The above post is reprinted from materials provided by KTH The Royal Institute of Technology. Note: Materials may be edited for content and length.

Journal Reference:
  1. Guo-Dong Wang, Weiwei Zhai, He-Chuan Yang, Lu Wang, Li Zhong, Yan-Hu Liu, Ruo-Xi Fan, Ting-Ting Yin, Chun-Ling Zhu, Andrei D Poyarkov, David M Irwin, Marjo K Hytönen, Hannes Lohi, Chung-I Wu, Peter Savolainen, Ya-Ping Zhang. Out of southern East Asia: the natural history of domestic dogs across the world. Cell Research, 2015; DOI: 10.1038/cr.2015.147


KTH The Royal Institute of Technology. "New twist in tale of dogs' origins." ScienceDaily. ScienceDaily, 16 December 2015. <www.sciencedaily.com/releases/2015/12/151216082339.htm>.
 

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