CNN News:科学家寻找最古老犬种

Which of these dog breeds is believed to be the oldest? Afghan Hound, Alaskan Malamute, Border Collie or Chihuahua. Many scientists believe the Afghan Hound originated in Afghanistan in around 6.000 B.C. making it the oldest breed on this list.

There's widespread disagreement over what the oldest breed in the world is. Some scientists say it's the Akita Inu, the Basenji or the Chinese Saluki. And while the relationship between people and dogs is known to go back thousands of years, researchers don't know exactly when or why dogs became domesticated as man's best friend. But there are some new theories about this and a related study was just published in the "Proceedings of the National Academy of Sciences".

What researchers did was compare genetic information gathered from ancient human remains with the info gathered from ancient dog remains. They say that some of the dogs found in the Americas have lineage that could be traced back to ancient Siberian dogs.

So from that, they concluded that when people migrated from Northeast Asia to the Americas, the dogs came with them. Scientists believe this happened more than 15.000 years ago over the Bering Land Bridge which no longer exists. The study lead author theorized that the dogs could have helped the people carry their goods faster and she suggested that people and dogs might have gotten together in the first place when humans allowed wolves to eat whatever food people threw away.

There's no definitive proof of this but researchers are hoping the search for older dog bones in the region of Siberia to get more evidence. So I guess you could say that some scientific studies have gone to the dogs.