“A 90-year-old tuft of hair has yielded the first complete genome of Aboriginal Australians. In 1921, the hair was donated to British anthropologist Alfred Cort Haddon when he was traveling through Golden Ridge in Western Australia. Two new genomics studies have shed light on the earliest migrations of humans by showing that the ancestors of present-day Aboriginal Australians left Africa around 70,000 years ago, which is at least 24,000 years before the migration that gave rise to present-day Europeans and Asians . The first of the studies, led by Rasmussen from the University of Copenhagen and published in Science, was conducted by sequencing the DNA from the lock of hair. While the DNA had degraded somewhat, researchers were still able to sequence and assemble most of it and compare it to the genomes of other populations around the world. The DNA showed no traces of the signature genetic fingerprints of modern European and Asian, suggesting Aboriginal Australians left Africa in the first great human migration from the cradle of humanity . Aboriginal Australians therefore descend directly from the earliest modern explorers, people who migrated into Asia before finally reaching Australia about 50,000 years ago. In showing this, the study establishes Aboriginal Australians as the population with the longest association with the land on which they live today. The history of Aboriginal Australians plays a key role in understanding the dispersal of the first humans to leave Africa. Archaeological evidence establishes modern human presence in Australia by about 50,000 years ago, but this study re-writes the story of their journey there”, the media reported yesterday.
“Previously, the most widely accepted theory was that all modern humans derive from a single out-of-Africa migration wave into Europe, Asia, and Australia. In that model, the first Australians would have branched off from an Asian population, already separated from the ancestors of Europeans. However, this study shows that when ancestral Aboriginal Australians begun their private journey, the ancestors of Asians and Europeans had not yet differentiated from each other . Once they did, some 24,000 years after the first Australians had begun their explorations, Asians and remnants of the ancestral Australians intermixed for a period of time. The second study, led by David Reich, Professor of Genetics at the Harvard Medical School and published in the American Journal of Human Genetics, found that the forebears of Aboriginal Australians interbred with another archaic human population called Denisovans, who ranged from Siberia to Southeast Asia. Aboriginal Australians, Near Oceanians, Polynesians, Fijians, east Indonesians, and Mamanwa (a Negrito group from the Philippines) have all inherited genetic material from Denisovans, but mainland East Asians, etc have not. These results suggest that relatives of present-day East Asians were not in Southeast Asia when the Denisova gene flow occurred “, the media added. This new discovery just adds another new fact to the incomplete story of Human Evolution .