Genetic testing conducted on the Iñupiat people of Alaska's North Slope could reveal the migration patterns of people who have lived in the North American Arctic over the past 5,000 years.
The recent study found all mitochondrial DNA haplogroups that have been found in the ancient remains of Neo- and Paleo-Eskimos and living Inuit individuals from North America were present in the people living in North Slope villages," Northwestern University reported.
"This is the first evidence that genetically ties all of the Iñupiat and Inuit populations from Alaska, Canada and Greenland back to the Alaskan North Slope," said Northwestern's M. Geoffrey Hayes, senior author of the new study to be published April 29, 2015, in the American Journal of Physical Anthropology.
The new findings support the archaeological model that determines people arrived in the North Slip in an eastward migration from Alaska to Greenland. It also supports the hypothesis that two major migrations occurred from the North Slope to the east.
"There has never been a clear biological link found in the DNA of the Paleo-Eskimos, the first people to spread from Alaska into the eastern North American arctic, and the DNA of Neo-Eskimos, a more technologically sophisticated group that later spread very quickly from Alaska and the Bering Strait region to Greenland and seemed to replace the Paleo-Eskimo," Hayes said. "Our study suggests that the Alaskan North Slope serves as the homeland for both of those groups, during two different migrations. We found DNA haplogroups of both ancient Paleo-Eskimos and Neo-Eskimos in Iñupiat people living in the North Slope today."
The research team took saliva samples from 151 volunteers living in eight different North Slope communities. They sequenced and analyzed the mitochondrial DNA present, which is passed from mother to child. The analysis revealed 98 percent of the maternal lineages in this group were of Arctic descent, and contained all know haplogroups which included A2a, A2b, D4b1a and D2.
Until this study, D2 had only been found in ancient Plaeo-Eskimos. D4b1a is a known haplogroup of the ancient Neo-Eskimo that came after the Paleo-Eskimos and is believed to have replaced them in most of the Arctic.
"We think the presence of these two haplotypes in villages of the North Slope means that the Paleo-Eskimos and the Neo-Eskimos were both ancestors of the contemporary Iñupiat people," said Jennifer A. Raff, first author of the study and a post-doctoral fellow in Hayes' lab at the Feinberg School when the research was being done. "We will be exploring these connections in the future with additional genetic markers."
The C4 haplogroup was generally only seen in Native Americans that lived much farther south. It's presence suggests it may have been present in the earliest humans to populate the Americas, and may have reached the North Slope through marriages between Athapascan and Iñupiat families. Another surprise revealed by the data was evidence that there may have been migrations of Greenlandic Inuit back to the Alaska North Slope.
"We found that there were many lineages shared between villages along the coast, suggesting that women traveled frequently between these communities," Hayes said. "In fact, when we compared the genetic composition of all the communities in the North Slope, we found that they were all so closely related that they could be considered one single population. This fits well with what the elders and other community members have told us about Iñupiat history."
In the future, the researchers plan to analyze genetic markers on the Y-chromosomes from men in the North Slope in hopes of gaining more valuable insight into the history of this group, and determining how contact with outsiders in the 19th century influenced the genetics of the Iñupiat people.
The findings were published in a recent edition of the American Journal of Physical Anthropology.