Arctic Science Journeys
Radio Script
1996

__________________

Eskimo Ancestors
__________________

Peter Underhill is among a team of Stanford geneticists studying mutations in the male Y-chromosome. By finding these mutations and seeing if they occur among other cultures, scientists can discover how seemingly different cultures may be related.

Recently, the Stanford research team did just that, when they discovered a genetic mutation on the Y-chromosome of Alaskan Eskimo males. They also discovered the mutation was present in the males of the three broadly defined groups of North and South American Indians. The mutation's presence makes it likely that these now very distinct cultures share a common ancestor. Stanford's Peter Underhill.

"The interesting thing is that some of the Eskimos at least have this genetic signature that is found in other Native American Indian groups, and this particular genetic signature is not found anywhere else in the world, at least based on the sampling we have done to date."

On any chromosome, each gene location is identified by a letter that stands for the particular protein the gene is made of. At the site where the mutation was found, the scientific code should be a C, for the protein cytosine. But somewhere along the line the code mutated from a C to a T, for Thymine. Underhill says the harmless mutation must have occurred in the sperm of one male as many as 30,000 years ago.

"And that one sperm went on to successfully fertilize one egg. And that offspring, then his son, turned out to have T-Y chromosome. The Y- chromosome is directly passed from father to son to grandson ect. Where on the Y-chromosome hundreds of generations could occur and once a mutation has happened it is passed on and it persists."

Anthropologists and archeologists have amassed a great deal of evidence such as tools and other artifacts that suggests the first Americans came to Alaska across a land bridge that once connected Asia to Alaska. Underhill says other researchers likely will look to see if this genetic mutation exists on Asian cultures thought to be the original descendants of the Alaska Eskimo and American Indian. If scientists are able to make such a connection, it would help finally prove who Alaska Eskimos' most distant ancestors are, and perhaps even when the new world was first populated.

For Arctic Science Journeys, this is Debra Damron.