London: Scientists have created a DNA tool that can accurately identify ancient populations, and may be used to test an individual's similarity to ancient people who once roamed the earth. Currently the study of ancient DNA requires a lot of information to classify a skeleton to a population or find its biogeographical origins.
Scientists at the University of Sheffield in the UK have defined a new concept called Ancient Ancestry Informative Markers (aAIMs) -- a group of mutations that are sufficiently informative to identify and classify ancient populations.
The research, led by Eran Elhaik, from University of Sheffield in the UK, saw the identification of a small group of aAIMs that can be used to classify skeletons to ancient populations.
"We developed a new method that finds aAIMs efficiently and have proved that it is accurate," said Elhaik. AIMs (Ancestry Informative Markers) have a long history in science and have been employed for the past decade by health and forensic experts.
Elhaik said that when his team applied traditional aAIMs-finding tools to ancient DNA data, they were disappointed with their low accuracy. "Ancient populations are much more diverse than modern ones. Their diversity was reduced over the years following events such as the Neolithic revolution and the Black Death," said Elhaik.
"Although we have many more people today they are all far more similar to each other than ancient people. In addition, the ancient data themselves are problematic due to the large amount of degraded DNA," he said. To overcome these challenges, Elhaik developed a specialised tool that identifies AIMs by combining traditional methodology with a novel one that takes into account a mixture.
"Until now you couldn't test people for ancient DNA ancestry because commercial microarrays, such as the ones used for genetic genealogy, don't have a lot of markers relevant for paleogenomics -- people could not study their primeval origins," Elhaik said. "This finding of aAIMs is like finding the fingerprints of ancient people," he said.
"It allows testing of a small number of markers -- that can be found in a commonly available array -- and you can ask what part of your genome is from Roman Britons or Viking, or Chumash Indians, or ancient Israelites, etc," he added.
Researchers said to make the findings more accurate for identifying and classifying ancient people throughout the world, the framework and methods of the study should be applied again when more comprehensive ancient DNA databases are available.