Saliva samples could reveal ancient Alaskan's descendants

Saliva samples could reveal ancient Alaskan's descendants
Natives' DNA may match cave man's
By GEORGE BRYSON
Published: June 6th, 2008 12:29 AM

Tlingit, Haida and Tsimshian Indians gathering in Juneau today will get a chance to prove they're directly related to one of the very first Alaskans -- a 10,300-year-old mariner whose bear-chewed bones were discovered a decade ago in a cave on Prince of Wales Island.

In return, molecular anthropologists collecting the participants' DNA hope to add to their knowledge about how the earliest Americans spread across the western hemisphere -- possibly along a coastal sea route -- in spite of the ice-choked plains.

First, however, they'll have to gather a little saliva, about a single milliliter per customer, by inducing potential relatives of the ancient Alaskan to spit into a laboratory test tube.

The fact that Southeast Native elders approve of the experiment -- just as they earlier endorsed requests to examine the human remains -- contrasts sharply with the protests and pitched legal battles Indian leaders in Washington state waged over the fate of "Kennewick Man," the 9,000-year-old Columbia River skeleton.

Tlingit elder Rosita Worl, president of the Sealaska Heritage Institute -- the Southeast Alaska Native nonprofit group that's helping stage the study -- partially credits the institute's Council of Traditional Scholars.

"When this 10,300-year-old person was found on Prince of Wales, the way it was interpreted was that we had one of our ancestors offering himself to give us knowledge," Worl said. "They were also saying that if our culture is going to survive and flourish, then we have to be receptive to science."

It was a former Alaska scientist named Tim Heaton, a paleontologist, who discovered the ancient bones in 1996. He'd been conducting an archaeological survey on the northern tip of Prince of Wales Island -- about 140 miles south of Juneau -- in a place called On Your Knees Cave.

The bones themselves were few and superficially unimpressive: a molar-filled jaw recovered in two pieces, the partial remains of a pelvis, three ribs, some vertebrae, a scattering of teeth.

Lead archaeologist E. James Dixon initially dated the bones at more than 9,000 years old, making them the oldest human remains ever discovered in Alaska or Canada. And with Heaton's help, he began to piece together the cave man's story.

The teeth indicated he died in his prime, possibly early to mid-20s. The content of his bones revealed that his primary food came from the sea. The nearby stone tools -- consisting of materials not found on the island -- suggested a long-distance traveler. And his final resting place filled with bear bones (including the femur of a 35,000-year-old grizzly), coupled with signs that his own bones had been chewed on by a large carnivore, spoke of dying a violent death.

Most importantly, however, the evidence indicated that On Your Knees Cave man was a prime example of a relatively new theory about how the first people may have spread across the Americas, even before the last ice age ended.

PADDLING THE COAST

Scientists used to think migrating groups simply walked across the 1,000-mile-wide Bering Land Bridge and bided their time around present-day Fairbanks -- at least until about 12,000 years ago, when the glaciers that blocked the center of the continent finally began to melt, opening an ice-free corridor south.

But that long-accepted migration theory has grown problematic of late, as scientists keep discovering evidence of earlier Americans living south of Alaska -- including humans in Monte Verde, Chile, 12,500 years ago, and on an island off California 13,000 years ago, and inside a coastal Oregon cave 14,300 years ago.

They could have got there, some scientists believe, simply by paddling the coast. One who thinks so is Washington State molecular anthropologist Brian Kemp, who spent two years as a graduate student trying to tease DNA from On Your Knees Cave man's bones. Eventually he succeeded, using a tooth -- specifically dated at 10,300 years old -- which yielded the oldest DNA sample in the western hemisphere.

Examining it for mitochondria DNA -- the genetic marker passed down through millennia only by mothers-- Kemp determined that the Prince of Wales man was a member of Haplogroup D, one of five genetic groups that comprise all Native Americans.

But only about 15 out of every 100 Native Americans who've been sampled are Ds. Among them are very few Native Alaskans. There no known Tlingits, Haidas, Athabascans or Inupiats, though about two-thirds of sampled Aleuts are Ds and, so far, one Yupik.

Kemp, however, took his DNA study one step further by classifying On Your Knees Cave man into a narrower genetic subgroup known as D3H4 -- which represents less than 2 percent of all Native Americans. Then he located all members of the subgroup on a map, drawing upon prior genetic studies of both living and deceased Native Americans.

What emerged was the image of nearly all of On Your Knees Cave man's closest genetic relatives clinging to the West Coast from California to the tip of Argentina -- perhaps mirroring an ancient pathway south.

"I thought that was fantastic," said Kemp, whose study was published last year in the American Journal of Physical Anthropology. "It was evidence of a coastal migration."

A DISTANT COUSIN?

Kemp himself was scheduled to travel the coast this week -- to Juneau, where he hopes to gather more DNA. According to Worl, the scientists should have pretty good luck.

The Sealaska Heritage Institute has been actively promoting the research as part of its biennial Celebration 2008 festivities, which began Thursday and conclude on Saturday. More than 5,000 Native Alaskans are expected to attend the celebration.

Chances that any of them who participate in the DNA study will turn out to be directly related to On Your Knees Cave Man are relatively slim, Kemp said, partly because populations move around so much (the Tlingit and Haida people, for example, are closely related linguistically to Interior Athabascans and may have moved to Alaska a few thousand years ago from a home farther south).

"It may be that we're not going to find the same DNA in the present population," said Worl, a Harvard-trained anthropologist. "I'm totally aware of that."

But that doesn't mean that the Tlingit, Haida and Tsimshian people of Southeast Alaska aren't related to On Your Knees Cave man, she said. He's at least a cousin, and maybe more than that.

Said Worl: "As far as we're concerned, he's still our ancestor."

Last year, the Forest Service conveyed custody of On Your Knees Cave man's bones to the Tlingit tribes in Klawock and Craig, marking the first time a federal agency has transferred human remains that old to a Native American tribe. This fall the tribes plan to rebury the remains on Prince of Wales Island.