Research on a newly discovered 9000-year-old childhood teeth has transformed our understanding of Alaska's ancient people, their genetic background and their diets.
The tooth is just the third known remnant of a population of early immigrants known as ancient Beringians. Combined with earlier University of Alaska Fairbanks surveys indicate the feature that ancient Beringians remained in Alaska for thousands of years after moving over the Bering Land Bridge that linked eastern Asia and Alaska.
Examination of the teeth, conducted by UAF researchers and National Park Service in Alaska, was part of a larger paper published November 8 in the newspaper Science. That research included genetic analysis of 15 different bone samples from places in North and South America, revealing a broad picture of how America populated its earliest people.
The Alaska tooth had been largely forgotten since it was dug out in 1949 by Danish archaeologists from the Trail Creek Caves site on the Alaska Seward Peninsula. For nearly 70 years, it has been held in Copenhagen, Denmark, until it was found in 2016 by Jeff Rasic, a Fairbanks-based NPS archaeologist who conducted new analyzes of this old collection.
Radiocarbon dating determined the teeth, belonging to a 1½ year old child, is by far the oldest human example in the North American arctic – more than twice as old as the next oldest remnant. Genomic testing coupled the tooth to the old bering line. The first traces of that population were discovered in 2013 by a team led by UAF Professor Ben Potter in a place in Alaskan's interior.
"This little tooth is a source of taxation of information about Alaskan's early populations, not just their genetic affinities but also their movements, interactions with other people and diets," Rasic said.
Looking at each other, the two sides – separated by about 400 mil and 2,500 years – show that the ancient bersians were present over the vast expansion of Alaska for millennia.
"This new discovery confirms our predictions that antique bears are directly linked to the cultural group called Denali Complex, which was widespread in Alaska and the Yukon Territory from 12,500 to about 6000 years ago," said Potter, who was not involved in the science paper .
Researchers worked with tribal officials from Seward Peninsula Village Deering to coordinate efforts to study dental care.
Analysis at the UAF Alaska Stable Isotope Facility also revealed surprising details about the child's life and, by proxy, the mother who fed the child. By studying chemical signatures preserved in the teeth, ASIF director Matthew Wooller could analyze his diet.
"The children's food sources were completely terrestrial, a sharp contrast to other places that indicate that anadromous fish and marine resources are included." said Wooller, who also works at the UAF Fisheries and Sea Sciences College and the Water and Environmental Research Center.
The land-based diet is a surprise – during the time the child lived on the Seward Peninsula, sea levels have risen to almost modern levels. The rising waters had cut off Bering Land Bridge and surrounded most of the peninsula, which meant that marine resources were available.
Further isotope results and modeling, conducted by Rasic, Wooller and Clement Bataille of the University of Ottawa, also determined the family resident in the region around the caves and were not immigrants from elsewhere in Alaska or Siberia.
"The combination of isotope signatures found in the teeth is quite specific to the inner Seward peninsula, which makes a local origin for the family very likely," said Bataille.