BBC: 11/22/02: scientists believe dogs evolved from just a few wolves tamed by humans living in or near China 15,000 years ago

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Friday, 22 November, 2002, 05:03 GMT

Origin of dogs traced

 

By Christine McGourty

BBC science correspondent

 

Dogs today come in all shapes and sizes, but scientists believe they

evolved from just a handful of wolves tamed by humans living in or

near China less than 15,000 years ago.

 

It looks as if 95% of current dogs come from just three original

founding females

 

Matthew Binns, Animal Health Trust Three research teams have

attempted to solve some long-standing puzzles in the evolution and

social history of dogs.

 

Their findings, reported in the journal Science, point to the

existence of probably three founding females - the so-called " Eves "

of the dog world.

 

They conclude that intensive breeding by humans over the last 500

years - not different genetic origins - is responsible for the

dramatic differences in appearance among modern dogs.

 

One team studied Old World dogs to try to pin down their origins,

previously thought to be in the Middle East.

 

The other team studied dogs of the New World and found they are not

New World dogs at all, but also have their origins in East Asia.

 

Carles Vila, of Uppsala University, Sweden, one of the team studying

the New World dogs, told BBC News Online: " We found that dogs

originating in the Old World arrived to the New World with

immigrating humans.

 

" Thus, even before the development of trade as we know it now, humans

had to be exchanging dogs. "

 

He added that exactly how or why humans domesticated dogs was not

known, but the speed at which they seem to have multiplied and

diversified indicates they played an important role in human life.

 

" I can imagine that if dogs were, for example, improving the quality

of hunting, that would be a very great advantage for humans. It could

even have made the colonisation of the New World easier.

 

" There must have been something advantageous about those dogs that

made them extremely successful and allowed them to spread all over

the world. "

 

Peter Savolainen, of the Royal Institute of Technology, Stockholm,

led the study of Old World dogs, analysing DNA samples taken from

dogs in Asia, Europe, Africa and arctic America.

 

'Bit of a surprise'

 

His team found that, though most dogs shared a common gene pool,

genetic diversity was highest in East Asia, suggesting that dogs have

been domesticated there the longest.

 

" Most earlier guesses have focused on the Middle East as the place of

origin for dogs, based on the few known facts - a small amount of

archaeological evidence from the region, and the fact that several

other animals were domesticated there, " he says.

 

The researchers studied gene sequences from the dogs' mitochondrial

DNA, which is inherited directly from the mother. The findings

indicated that the major present-day dog populations at some point

had a common origin from a single gene pool.

 

Matthew Binns, head of genetics at the Animal Health Trust in

Newmarket, UK, said the findings were significant.

 

He told BBC News Online: " For the first time, there's relatively

convincing evidence actually pinpointing the date at which the dog

was domesticated and also the location of that domestication, which

is a bit of a surprise.

 

" People have previously thought that a lot of species were

domesticated in the Middle East and this data clearly shows

domestication took place in East Asia. "

 

He added: " It looks as if 95% of current dogs come from just three

original founding females and I guess these are the Eves of the dog

world. "

 

Human evolution

 

In a separate study, researchers at Harvard University and the Wolf

Hollow Wolf Sanctuary, both US, studied social cognition in dogs and

were surprised by the findings.

 

In a simple experiment designed to compare their behaviour to those

of wolves and our closest relative, the chimpanzee, the findings

clearly showed that dogs - even young puppies - were far better at

interpreting social cues from humans.

 

The dogs had to choose which bucket had food hidden underneath it,

and the experiment was designed so they could not rely on their

superb sense of smell. The scientists helped by pointing or looking

in the direction of the hidden food.

 

Researcher Brian Hare said the dogs outperformed even the

chimpanzees, and the puppies were as good as the older dogs, proving

the skill was innate and not learned.

 

" During domestication there was some kind of change in their

cognitive ability that allowed them to figure out what other

individuals wanted using social cues. The biggest surprise was the

puppies - even as young as nine weeks old, they're better than an

adult chimpanzee at finding food. "

 

He said the research might ultimately provide some clues as to how

social skills evolved in humans.

 

 

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