Dogs and humans have been together for 33000 years

Man’s best friend came about after generations of wolves scavenged alongside humans more than 33,000 years ago in south east Asia, according to new research.

Scientists examined the genetic make-up of wolves and dogs from China, Africa and Europe, to discover domesticated dogs evolved from the first grey wolves that joined humans on ancient scavenging missions.

While prior scientific research indicated that the first domesticated dogs descended from European wolves 10,000 years ago, new DNA analysis shows that that the first domesticated dogs actually appeared 33,000 years ago.

Peter Savolainen, an evolutionary geneticist at the Royal Institute of Technology in Solna, Sweden, and co-author of the paper, has spent the past 15 years studying dog DNA, trying to discern the canine’s journey from aggressive and fearful wolf to man’s best friend.

The history of dog domestication is often depicted as a two-stage process where primitive dogs were first domesticated from their wild ancestors, the gray wolves.

The origin of dogs has inspired a lingering controversy in academia.

“The long persistence of the domestic dog lineage in southern East Asia opens up for interesting scenarios”. It also confirms earlier studies that Savolainen did with mitochondrial DNA.

Another study from the same group in 2009 further limited this glut of genetic diversity to dogs from the area around southern China, northern Thailand, Vietnam and Laos – what researchers call “southern East Asia”. They found that around 10,000 years ago the domesticated canines made their way to Europe when humans began to builds villages and farmsteads.

The researchers collected the genome sequences of 58 canids from across the world, including samples from Europe, Africa, southern and northern parts of East Asia, the Middle East, Siberia and the Americas.

Other studies that look at additional genetic markers, such as tiny snippets of DNA from across the genome, have pointed to Europe or the Middle East as the likely origin of dog domestication. The ancestral dog and wolf may have continued to interbreed for a while, but the scientists are confident enough of their findings not only to put a date for the emergence of what became the domestic dog – around 33,000 years ago – but even to guess at an original or founder population of about 4,600 individuals. That included breeds long associated with specific geographical locations, such as the Afghan hound (Central Asia), the Sloughi (North Africa), the Alaskan malamute and the Siberian husky (Arctic and Siberia) and the Chihuahua (the Americas).

But the dog ancestors may have initiated their own journey from South East Asia because of environmental factors, such as the retreat of glaciers, which started about 19,000 years ago. Tibetan Mastiffs are thought to be one of the world’s oldest breeds.

One of the lineages that evolved outside Asia also migrated back to the East, creating a several admixed populations. “As a single species, the domestic dog embodies one of the largest collections of phenotypic diversity for any species living on earth”.

“Our study, for the first time, begins to reveal a large and complex landscape upon which a cascade of positive selective sweeps occurred during the domestication of dogs”, the scientists write.