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#1 02-05-2018 10:23:41

Date d'inscription: 24-10-2016
Messages: 1145

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WASHINGTON, June 2 (Xinhua) -- Dogs may have been domesticated not once, as widely believed, but twice, once in Europe and once in Central Asia or China, a major study said Thursday.

Scientists have debated where domestic dogs come from for a very long time. Some argued that humans first domesticated wolves in Europe, while others claimed this happened in Central Asia or China.

All these claims, according to the new study published in the U.S. journal Science, may be right.

The study, supported by funding from the European Research Council and Britain's Natural Environment Research Council, said that man's best friend may have emerged independently from two separate, possibly now extinct, wolf populations that lived on opposite sides of the Eurasian continent.

The team, led by the University of Oxford and including French researchers based in Lyon and at the National Museum of Natural History in Paris, made the conclusion after reconstructing the evolutionary history of dogs.

They first sequenced the genome of a 4,800-year-old medium-sized dog from bone excavated at the Neolithic Passage Tomb of Newgrange, Ireland.

Then, they obtained mitochondrial DNA from 59 ancient dogs living between 14,000 to 3,000 years ago and compared them with the genetic signatures of more than 2,500 previously studied modern dogs.

Their analyses revealed a genetic separation between modern dog populations currently living in East Asia and Europe, one they said occurred several thousand years after the first known appearance of dogs in Europe.

The new genetic evidence also showed a population decline in Europe that appeared to have mostly replaced the earliest domestic dog population there, which supported the evidence that there was a later arrival of dogs from elsewhere.

Lastly, a review of the archaeological record showed that early dogs appeared in both the East and West more than 12,000 years ago, but in Central Asia no earlier than 8,000 years ago.

Combined, these new findings led the researchers to believe that dogs were first domesticated from geographically separated wolf populations on opposite sides of the Eurasian continent.

At some point after their domestication, the eastern dogs dispersed with migrating humans into Europe where they mixed with and mostly replaced the earliest European dogs.

Most dogs today are a mixture of both Eastern and Western dogs -- one reason why previous genetic studies have been difficult to interpret, they said.

The international project is currently analyzing thousands of ancient dogs and wolves to test this new perspective, and to establish the timing and location of the origins of our oldest pet.

""Animal domestication is a rare thing and a lot of evidence is required to overturn the assumption that it happened just once in any species,"" senior author Greger Larson, professor of the Oxford University, said in a statement.

""Our ancient DNA evidence, combined with the archaeological record of early dogs, suggests that we need to reconsider the number of times dogs were domesticated independently,"" he said.

""Maybe the reason there hasn't yet been a consensus about where dogs were domesticated is because everyone has been a little bit right,"" he added. Enditem


KABUL Connor Barwin Youth Jersey , April 22 (Xinhua) -- Taliban militants fighting the Afghan government to regain power announced Wednesday to launch their annual spring offensive.

The offensive dubbed "Azm" means "Resolution" from Friday April 24, a statement of the armed outfit sent to media said. "Although the foreign occupying forces announced late last year the end of war mission in Afghanistan Samson Ebukam Youth Jersey , still they control the land and air space of the country and the command of war is in their hands," the statement said Josh Reynolds Youth Jersey , adding if the foreign occupiers want the end of war in Afghanistan, they should withdraw completely.

The U.S. and NATO-led troops ended their combat mission in Afghanistan late in December 2014 John Johnson Youth Jersey , facilitating Afghan national security force to shoulder alone the security responsibility of the their conflict-ridden country from January 1 this year.

However, more than 13 Gerald Everett Youth Jersey ,000 U.S.-led forces under the name of Resolute Support (RS) mission have still remained in Afghanistan to train and advice Afghan forces.

In the statement, Taliban militants also called upon Afghan civil and military servicemen to desert government rank and join "Islamic Emirate of Afghanistan" (the name of Taliban ousted regime) which had ruled major part of the country before its collapse in late 2001.

The announced annual spring offensive is the first one since President Ashraf Ghani assumed office in September.

Taliban outfit in its last spring offensive Derek Carrier Jersey , dubbed "Khyber" and kicked off on May 12, 2014 mostly in the shape of suicide attacks and roadside bombings Ethan Westbrooks Jersey , had failed to capture a major city or district in the country although thousands of people including militants, military personnel and civilians were killed and injured.

Nearly 3 John Sullivan Jersey ,700 civilians were killed and more than 6,800 others injured in the Taliban-led militancy and conflicts in 2014 Tyrunn Walker Jersey , according to a report of UN mission in Afghanistan released here in February this year.

Militancy and conflicts typically get momentum in spring and summer in Afghanistan commonly known as fighting season among Afghans.

MOMBASA, Kenya, March 12 (Xinhua) -- Kenyan President on Sunday ruled out further talks with the striking doctors and directed them to return to work before any more talks.

State House Spokesperson Manoah Esipisu told journalists in Mombasa that Kenyatta ordered the doctors who have been on strike sine December 5, 2016 to resume work if they wish to have the government to engage them in more negotiations.

"President Kenyatta has directed that all doc.

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