10,300 YEARS OLD: Tests of Southeast Natives challenge prior anthropological results. An ancient mariner who lived and died 10,000 years ago on an island west of Ketchikan probably doesn't have any close relatives left in Alaska. But some of them migrated south and their descendents can be found today in coastal Native American populations in California, Mexico, Ecuador, Chile and Argentina. That's some of what scientists learned this summer by examining the DNA of Tlingit, Haida and Tsimshian Indians in Southeast Alaska. Working with elders at a cultural festival in Juneau, they interviewed more than 200 Native Alaskans who allowed...