Monday, March 13, 2006

Hunted by Giant Hyenas?

Christy Turner, the eminent anthropologist who is famous (or infamous) for demonstrating conclusively that the Anasazi practiced cannibalism, has been working for years now in the Altai mountains of a bigger "Four Corners", where Siberia, Mongolia, Kazakhstan, and Xinjiang come together. He has been looking for the answer to a riddle: why did humans "hang up" for as long as 40 or 50 thousand years before they entered Siberia and the land bridge of Beringia to the new world? In this ABC Science post, he suggests an answer: he thinks that humans there were preyed on by packs of huge hyenas-- and that the domestication of the dog may have tipped the scales in favor of the dog- human partnership.

"Part of the evidence comes from a remarkable cave that was occupied solely by hyenas for about 40,000 years. Turner, who is also a dental anthropologist, examined bones found in the cave and concluded that all of the animals in the cave were dragged there by hyenas.

"Most animals gnaw at a bone, or rip it open with slicing molars, but a hyena just crushes it. Even a bear can't do that. The bones found in the cave, Turner says, were clearly there because of the hyenas.

" "But one set of bones especially intrigues Turner.

" "We found a true dog skull," he says. "We've dated the skull to about 14,000 years ago, and it's a domesticated dog," so much smaller than a wolf that it would not have survived if it had not been domesticated. The dog, he adds, was dragged into the cave, where it was devoured by hyenas.

"It's the oldest dog ever found in Siberia, Turner says, and it was domesticated just before humans started their migration north, leading them eventually to the Americas.

" "The coincidence is so remarkable," he says. "Once we get the dog, then we get people in the new world almost immediately."

I actually corresponded with Turner on this matter a few years ago-- as you may know, I am endlessly researching the idea that Central Asia is the wintry Eden of domestication, and especially of dog domestication (of course I am also interested in the "First Americans" question, and this links both!) Nothing proven yet, and DNA tends to support dates earlier than 14,000 YA for dog- wolf DNA separation, but those very first dogs may have been camp followers only. Maybe when they became more useful, the humans could begin to trek again...

Hat tip to Chas, whose take is wittier than mine.


Steve Sailer said...

Steve, you should talk to the HapMap scientists like Moyzis, Wang, Pritchard, and Cochran. They are finding a ton genes that have undergone selection in the last few tens of thousands of years. Their initial reaction is to typically attribute this to agriculture, but dog domestication might fit into the picture as well.

Anonymous said...

Hyenas were amazingly diverse in the pleistocene. Along with the giant forms, there were also cursorial, cheetah-like forms (I think the genus name is euryboas for the North American form.). All told there were about five or six genera of hyenas during that time.

I imagine having an extra set of eyes, ears and teeth would have helped against meat eating heavyweights like arctodus simus, homotherium latidens, panthera leo atrox, smilodon fatalis and who knows, maybe even relict populations of titanis walleri.

I see no reason that this hypothesis would not extend well beyond hyenas. There were plenty of frightening beasts roaming about North America that dogs could have helped keep at bay.

-Arthur Wilderson