DNA testing has proved that diseases carried by Europeans arriving in the New World killed large numbers of Native Americans.
Scientists have carried out detailed analysis of the DNA extracted from 92 mummies and skeletons found in South America. The bodies were between 900 and 8,600 years old and have enabled researchers to rebuild a genetic history of people living in the region before the arrival of Christopher Columbus in 1492.
The research, which has now been published in Science Advances, shows that none of the genetic lineages found in these pre-Columbian people are present in the indigenous populations living in the Americas today, suggesting that colonisation brought about the extinction of these bloodlines.
One of the researchers involved in the study, Dr Bastien Llamas, from the University of Adelaide, said: “This separation appears to have been established as early as 9,000 years ago and was completely unexpected, so we examined many demographic scenarios to try and explain the pattern. The only scenario that fit our observations was shortly after the initial colonisation, populations were established that subsequently stayed geographically isolated from one another, and a major portion of these populations later became extinct following European contact.
“This closely matches the historical reports of a major demographic collapse immediately after the Spaniards arrived in the late 1400s.”
Scientists studied genes from maternal line
The study involved extracting DNA from bones and teeth discovered in the human remains. The researchers, who included scientists from the University of California and Harvard Medical School, then sequenced whole mitochondrial genomes – DNA which is passed down from the mother.
This latest study supports the long-held belief that tuberculosis brought by European settlers killed many indigenous people living in both North and South America. Previous studies have estimated that diseases from Europe wiped out around 19 million Native Americans – thought to be about 95 per cent of the total population.
Researchers now want to carry out more work comparing the DNA of these pre-Columbian people with those living in the Americas today.
The research also gives us a clearer idea of when the first people entered the Americas during the last Ice Age. It is thought they migrated there over the Beringian land bridge, a strip of land which connected the north-western tip of North America with Asia.
Director of the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide, Professor Alan Cooper, said: “Our genetic reconstruction confirms the first Americans entered around 16,000 years ago via the Pacific coast, skirting around the massive ice sheets that blocked an inland corridor route which only opened much later. They spread southward remarkably swiftly, reaching southern Chile by 14,600 years ago.”
While DNA testing can be used to discover more about the past, it can also solve much more current mysteries. It can be an important tool in establishing family relationships with paternity, maternity and sibling tests available.
It is also possible to find out whether you are biologically related to other potential members of your family including grandparents and aunties and uncles. One method of doing this is the Y Chromosome test. Y chromosomes are passed unchanged from father to son so if two men are related through their paternal line, this chromosome will be identical.
AlphaBiolabs offers the fastest and most accurate Y Chromosome test available in the UK.