Debate over the first domestication of wolves has long been a contentious issue, new ancient DNA evidence supports a one-off occurrence sometime between 40,000 to 20,000 years ago.
The history of the human domestication of wolves and the selective breeding that gave us ‘man’s best friend’ has long been dogged by controversy. Canine genetic research published in June 2016 supported the possibility of two separate domestication episodes, with wolves being first brought into service by modern humans living in East Asia followed by a similar process beginning in Europe – involving two distinct populations of wolves.
The latest study examined the complete genome of a 7,000-year-old dog from Herxheim, and a 4,700-year-old dog from Kirshbaumhöle, both located in Germany. The team of scientists also analyzed DNA extracted from a 4,800-year-old dog uncovered at Newgrange, Ireland. The genetic material from Newgrange had previously featured in the study that suggested two phases of canine domestication.
This latest round of analysis focussed on ancient dog DNA, strongly suggests that dogs parted ways from wolves, in terms of their genetic profile, sometime between 40,000 – 20,000 years ago. The researchers claim that their findings support a model in which East Eurasian and West Eurasian dogs became genetically distinct around 17,000 to 24,000 years ago – with dogs being domesticated just once.
Foot prints of an eight-year-old boy accompanied by a wolf have previously been recorded at the Chauvet Caves in France, home to some of Europe’s earliest cave art – these footprints confirm that wolves were living alongside humans at least 24,000 years ago.
As interesting as the latest findings are, it seems unlikely that the latest findings will settle the debate over the geographic location and exact timeline of the domestication of wolves and emergence of pet dogs.
Peter Savolainen, an evolutionary geneticist at KTH Royal Institute of Technology in Stockholm, remarked that the new study “puts dog origins into one time and place again. That’s really important,” before commenting further on the location for this process, “there’s a single origin, and it wasn’t in Europe.” Savolainen is recognised as a proponent of an East Asian origin of dogs.
Krishna Veeramah, an evolutionary geneticist at Stony Brook University in New York, points out that it is the proponents of multiple domestications for dogs that carry the burden of providing extraordinary evidence. Veeramah, who co-authored the paper, is adamant that his research team, “can explain all of our data just using one domestication event.”
Both camps of scientists recognise a split between East Asian and Western European dogs, the disagreement is only on whether that split happened after domestication took place. Modern European dogs still share heritage with Stone Age canines on the continent, hinting that all the pups came from a common source rather than separately domesticated Asian dogs replacing their European counterparts.
A family tree constructed from the DNA data puts today’s Southeast Asian breeds on the earliest branch, implying an origin in Asia. But a dog breed’s present-day location may not reflect where dogs were actually domesticated more than 20,000 years ago, Veeramah says.