Photo: Smithsonian Science

Genetics—the new spearheading tool for mapping America’s history

Biological systems Genes and genomes
Who were America’s first indigenous people? Danish scientists are now much closer to solving this mystery after mapping the entire genome of a boy belonging to the so-called Clovis culture, a tribe of mammoth hunters who lived about 12,000 years ago in North America.

Studies of the Clovis culture and their sophisticated technology for making spearheads has since led to intense debate among archaeologists as to the identity of America’s first indigenous people and their true origins.

Indians’ genetic origins
Genetics and modern sequencing technology has now come to the aid of archaeology. Together with an international team of scientists, Danish researchers have succeeded in sequencing the complete genome of a boy belonging to the Clovis culture. The DNA analysis results recently published in Nature show that the boy is so closely related to America’s present-day Indian population that it is possible to determine that the tribe to which he belonged is in fact the genetic origin of today’s Indian population living in Central and South America. The results also show that the Clovis people came to America from Northern Siberia and not from Europe, as previously suggested. However, it is now clear that Clovis were not the first people to inhabit America.   

Unique find
The new results are linked to the discovery of the skeleton of a two-year-old boy found near a farm in Montana in 1968. Alongside the skeletal remains, which are between 12,600 and 13,000 years old, scientists found a collection of so-called Clovis artefacts, including spearheads made using the specialized technology specific to Clovis culture. When Eske Willerslev and his research team from the Centre for Geogenetics at the University of Copenhagen were given permission to take a sample from the skeleton, there was sufficient DNA to carry out an in-depth DNA analysis.

Associate Professor Simon Rasmussen from the Centre for Biological Sequence Analysis at DTU Systems Biology tasked with processing the data of the prehistoric genome, explains:
“The Montana skeleton is a unique find and the DNA so well preserved that it was possible to perform 14X sequencing—i.e. scanning the DNA 14 times. This makes the genome the oldest human genome sequenced at such depth.”

Genes reveal more than link
And precisely the depth makes a huge difference to what can be extracted from the data, explains Simon Rasmussen, an expert in collecting genomes.

“The greater the depth, the greater the certainty of the results and the more you can determine. In addition to proving a link between the Clovis boy and the present-day Indian population, we are also able to say something about the boy’s appearance and what illnesses he was predisposed towards, etc. This is incredibly exciting and something we will be focusing on in the months ahead,” explains Simon Rasmussen.