Mummies can’t speak, but they’re beginning to disclose their secrets. Using ancient DNA, scientists have pieced together the genetic history of indigenous Americans, revealing the impact of European colonisation.
The researchers, led by the University of Adelaide's Australian Centre for Ancient DNA (ACAD), collected mitochondrial DNA samples from 92 Americanmummies and skeletons, all between 500 and 8,600 years old. This means that most of them lived before European explorers, led by Christopher Columbus, began to explore the continent in the late 1400s.
The scientists were surprised to discover that none of the genetic lineages from these ancient peoplecould be found in today’s indigenous populations. In other words, these lineages became extinct with the arrival of the Europeans.
"The only scenario that fit our observations was that shortly after the initial colonisation, populations were established that subsequently stayed geographically isolated from one another, and that a major portion of these populations later became extinct following European contact,” says Dr Bastien Llamas at the ACAD. “This closely matches the historical reports of a major demographic collapse immediately after the Spaniards arrived in the late 1400s."
The DNA samples also provided a more accurate timing for the arrival of the first people into the Americas, via the Bering land bridge that connected Asia and North America during the last Ice Age. The first Americans were found to arrive16,000 years ago via the Pacific coast, before spreading south across the continent.
To discover more about these first Americans, the researchers will continue to collect DNA from the indigenous populations and their modern ancestors. Who knows what other secrets the mummies may be guarding…
Image:La Doncella ('The Maiden') - an Incan mummy discovered in Argentinain 1999 -was one of those used in this study(credit:Johan Reinhard)
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