SCIENTISTS at the Australian Centre for Ancient DNA are part of an international team that has revealed a new family tree for modern Europeans that includes migration from Asia.
Published today in the journal Nature, the research points to a previously unknown genetic contribution in the ancestry of most modern European peoples.
“The new finding is that the genetic makeup of most Europeans living today has ancestry in at least three different groups of ancient people,” explained Dr Wolfgang Haak, Research Fellow with the Australian Centre for Ancient DNA at The University Adelaide.
Although previous studies had identified hunter-gatherers and Middle-Eastern farmers as two main groups of early humans in Europe, a third and a more mysterious population of Northern Eurasians is now known to have also been around.
“If we map it all out, it looks like the indigenous population of hunter gatherers started to appear in Europe from around 40 to 42,000 years ago,” said Dr Haak.
“Then the farming people moved through from the Middle East around 10,000 years ago.”
“Finally, this newly discovered third population arrived from the direction of Asia, from the Russian steppes,” he said.
Haak and his colleagues are now looking more precisely at when on the timeline this third group of ancestors arrived in Europe.
The Australian Centre for Ancient DNA specialises in conducting genetic analysis of human and animal body parts collected from field sites many hundreds to thousands of years after the time of death.
This research involved analysing the DNA in a 7,000-year-old early farmer from Stuttgart in Southern Germany, an 8,000-year-old hunter-gatherer from Luxembourg, and seven 8,000-year-old hunter-gatherers from Motala in Sweden.
Some 2,400 individuals from almost 200 diverse worldwide contemporary populations were also included in the study as examples of modern DNA.
Analysis of DNA from very old biological samples presents particular challenges.
“We have to be careful when we analyse ancient DNA,” said Dr Haak. “We work with small fragments of DNA, and the DNA is harder to find.”
“It becomes a big puzzle to not only find those smaller fragments but also to piece them together into something that is coherent and makes sense.”
Dr Haak and his colleagues use many layers of precaution during tissue collection and analysis to ensure the validity of their results.
“I was involved in analysis of the mitochondrial DNA from the bodies involved in this study” said Dr Haak.
“The beauty of this kind of DNA is that it’s passed on from generation to generation along the maternal line.”
“You can use it to trace particular populations, and when they came together or split geographically,” he said.
The study was performed by an international consortium led by researchers from the University of Tübingen in Germany and Harvard Medical School in the USA.