February 25, 2011

Earliest Sub-Arctic N. American Human Remains Found

The oldest human remains ever discovered in sub-Arctic North America have been unearthed in a newly excavated archaeological site in Alaska, scientists said on Thursday.

The skeletal remains appear to be those of a 3-year-old child buried some 11,500 years ago, and could provide rare insight into the burial practices of Ice Age peoples and the lives of early settlers who crossed from Asia to the New World, the scientists said.

The remains were discovered in an ancient fire pit within an equally ancient dwelling at the Upward Sun River site, near the Tanana River in central Alaska.

Radiocarbon dating of wood at the site indicates the cremation took place roughly 11,500 years ago, when the Bering Land Bridge may still have connected Alaska and Asia.  Initial observations of the teeth confirmed that the child is biologically affiliated with Native Americans and Northeast Asians.

The apparent age of the remains from the site would certainly make them the oldest human remains ever discovered in northern North America, and the second-youngest Ice Age child on the continent.

"This site reflects many different behaviors never before seen in this part of the world during the last Ice Age, and the preservation and lack of disturbance allows us to explore the lifeways of these ancient peoples in new ways," said University of Alaska, Fairbanks archaeologist Ben Potter, who along with four colleagues discovered the remains.

Both the burial and the house itself are the earliest of their kind known in sub-arctic North America.  

The discovery of the remains was unexpected, Potter said.

Indeed, discovery of burial sites of this age in North America is extremely rare.

Potter said that evidence of an older occupation in the area -- about 13,200 year ago "“ first attracted the researchers to the site.   Only while investigating this earlier occupation did evidence of the burial surface.

In a report about the findings, the researchers wrote that the pit contained not only the child's remains, but also remains of small mammals, birds, and fish and plants.  

The human remains were in the uppermost part of the pit, above the animal remains, leading researchers to suspect the pit was not originally designed as a grave.

Evidence also suggests the occupants abandoned the house after the cremation-burial.

The child has been named Xaasaa Cheege Ts'eniin [haw-SAW CHAG tse-NEEN], meaning "Upward Sun River Mouth Child."  The name is associated with the local Native place-name, Xaasaa Na' [haw-SAW NA], or Upward Sun River.  The site was formerly known as Little Delta Dune.

Although burned, some of the child's remains may retain DNA.

Based on the stratigraphy "” or examination of layers of materials in the fire pit "” and other evidence, the researchers describe a possible sequence for how the remains came to be interred at the site.

They suspect that a small group of people, including adult females and young children, were foraging in the vicinity of this residential camp, fishing and hunting birds and small mammals.  

A pit was dug within a house, used for cooking or perhaps as a means of disposing of food debris for weeks or months preceding the death of the child. The child died and was cremated in the pit, which was likely filled with surrounding soil soon thereafter.  The researchers concluded that the house was soon abandoned due to the lack of artifacts found above the fill.

Potter said the find is also significant because it crosses a number of disciplinary boundaries; the artifacts, features, stratigraphy, preservation and human remains allow for the integration and synthesis of stone tool technology, cultural affiliation, subsistence economy, seasonal use of the landscape, paleoenvironments and climate change in Ice Age northern North America.

Although the topic is still under debate, researchers generally believe that the first people in North America came across the Bering Land Bridge from Siberia some time near the end of the last ice age, around 13,000 years ago or earlier.   However, archaeological evidence from this time period is scarce, particularly in the northern regions adjacent to the Bering Sea, known as Beringia.

Scientists have discovered only a handful of known houses in North America from the continent's first 2,000 years of human occupation. And with the exception of the one at Upper Sun River, those houses are all in the lower 48 states or at Ushki Lake in Siberia.

The stone tools from contemporaneous sites in central Alaska fit into a category known as microblade technology, which consists of small, stone, razor-blade-like pieces set into larger organic points.

In contrast, the more well-known Clovis people of central North America did not make microblades.  In fact, the stone artifacts, along with the house structure and the types of animal remains found at Upper Sun River appear more similar to those of Siberia's Ushki Lake than to anything from the lower 48 states.

"We've got this basic technological organization system that links Alaska with the Old World," Potter said.

Researchers have debated over whether the people in central Alaska during the late Pleistocene and early Holocene were all part of one larger cultural group or whether they belonged to different groups.

The tools and other remains at Upper Sun River, and their similarities to some others in the region, support the former scenario, Potter and his colleagues say.

Differences exist among the sites, but these may reflect this people's versatility, with different members carrying out different tasks, such as hunting large game or foraging for small mammals and birds, during different times of year, the researchers speculate.

Potter and his team are working with Alaska Natives to ensure the excavation and subsequent examination of the remains will benefit science and heritage studies in a way that is respectful of traditional Athabascan culture. 

The local federally recognized tribe, Healy Lake Traditional Council, and its affiliated regional consortium, Tanana Chiefs Conference, sanctioned Potter and his colleagues' excavation and analysis.

"I would like to learn everything we can about this individual," said First Chief Joann Polston of Healy Lake Traditional Council, who said he would like to expand the opportunity to any Alaska Native in the region.

"This find is especially important to us since it is in our area, but the discovery is so rare that it is of interest for all humanity," said TCC President Jerry Isaac.

Potter called the collaboration a "fulfilling and productive partnership."

"We strove to be diligent with full and open negotiations from the time of discovery and before, and we have worked together to build a foundation for continued work on this find and for future discoveries," he said.

A report about the findings was published February 25 in the journal Science.

Potter's co-authors on the report are Irish and Carol Gelvin-Reymiller, both of UAF, and Joshua Reuther and Vance Holliday of the University of Arizona.


Image Caption: Joshua Reuther, Ben Potter and Joel Irish excavate the burial pit at the Upward Sun River site in Alaska. Credit: Ben A. Potter, University of Alaska Fairbanks


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