Feature:
DNA Reveals Dogs Have Been Human Companions For Over 30,000 Years“‘The domestic dog represents one of the most beautiful genetic sculptures shaped by nature & man.’
...This sentence comes from a fascinating study published... in the journal Cell Research, in which scientists from China, Canada, Finland, Singapore, Sweden, & the U.S. set out to trace the origin & evolution of the domestic dog.
Scientists have believed for a while in a 2-stage process; in the first stage, primitive dogs emerged from their wild ancestors, grey wolves. The idea was that the wolves began to hang around humans, perhaps because they found food nearby. Then, as they stayed with people, they became tamer, & started performing tasks like hunting & guarding. It was over a very long time... that the wolves became the first dogs. In the second stage, these primitive dogs were further selected into many different dog breeds...
This group of scientists...set out to unearth more specific details about how the domesticated dog evolved. To do this, they used the whole genome sequences, or complete sets of DNA, from 58 canids: 12 grey wolves, 27 primitive dogs from Asia & Africa, & a collection of 19 diverse breeds from across the world.
They found that dogs from south-east Asia have a much higher genetic diversity than all other populations of dogs, & relate most directly to grey wolves, & from this they deduced that domestic dogs originated in south-east Asia around 33,000 years ago, beginning with the grey wolf...
‘After evolving for several thousand years in east Asia, a subgroup of dogs radiated out of southern East Asia about 15,000 years ago to the Middle East, Africa as well as Europe. One of these out-of-Asia lineages then migrated back to northern China & made a series of admixtures with endemic east Asian lineages.’
...here’s the family tree of your pooch: about 33,000 years ago, his distant ancestor, the grey wolf, first made friends with a human. Jumping forward, about 15,000 years ago, a small group of domesticated dogs, descended from grey wolves, left home & headed for the Middle East & Africa. They made it to Europe about 10,000 years ago. And when humans first came to the Americas, they are thought to have brought dogs with them.
With the added twist that it’s possible some of the dogs trotted all the way back to China, & began interbreeding there...”
Judy M.
Dec. 21/2015
care2.com
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