A single lock of Aboriginal hair has revealed the genetic origins the first Australians and offered insight into the spread of early man.
Researchers have sequenced the DNA from a 100 year old lock of hair belonging to an Australian Aboriginal. The genome sequence has shown the Aboriginals were genetically separated from other human populations up to 75,000 years ago.
The findings rewrite the current understanding of man’s spread across the globe, suggesting that Aboriginal Australians are the descendants of a population whose exodus out of Africa preceded the journey of Asian and European ancestors by some 24,000 years.
You can see the University of Copenhagen’s researchers involved in the study discussing the results in the video above (courtesy of the University of Copenhagen).
The research comes hot on the heels of another paper examining Aboriginal genetics published this week in the American Journal of Human Genetics. The paper shows that Denisovans – a recently identified group of archaic humans – contributed DNA not just to present-day New Guineans, but also to Aboriginal Australian and Philippine populations. The results of the analyses agree with the Science research suggesting that – contrary to the findings of the largest previous genetic studies – modern humans settled Asia in more than one migration. You can read a media release from Harvard Medical School here.
The Australian Science Media collected the following expert commentary on the Science article examining Aboriginal DNA:
Professor Alan Cooper is Director of the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide
“It definitely strongly supports the idea that Aborigines were an early and separate wave of human expansion Out of Africa, before the subsequent wave that established Europeans and Asians. This has long been thought to be the case, due to the very early archaeological signs of Aboriginal presence in Australia (~50 kyr) and existing genetic data, but the highly-resolved view available from a genomic sequence is a really valuable contribution. While the information is only from a single individual, it provides a powerful view of the common, shared heritage of the movement of the ancestors of modern Aboriginal populations from Africa around half the world to Australia – which is one of the most important and poorly understood stories of human history.
“However, while this is a major step forward, the key unresolved question remains the unique story of Aboriginal history within Australia, ie what has happened in those 50,000 years of life in the harsh Australian environment? Unfortunately, the information from a single individual tells us very little about this fascinating, and critically important part of human history. Aborigines are one of the oldest continuous human populations outside Africa, as they note in the paper, and due to the geographic isolation and limited archaeological records – remain one of the most mysterious chapters in human history.”
Associate Professor Darren Curnoe is leader of the Human Evolutionary Biology Lab in the School of Biological, Earth & Environmental Sciences at the University of New South Wales
“This new DNA study powerfully confirms that Aboriginal Australians are one of the oldest living populations in the world, certainly the oldest outside of Africa.
“Their ancestors evolved on the African continent and were the first modern humans to arrive in Asia, the work confirming they have occupied Australia continuously since that time, perhaps 70 thousand years.
“Australians are truly one of the world’s great human populations and a very ancient one at that, with deep connections to the Australian continent and broader Asian region. About this now there can be no dispute.
“The study also confirms controversial claims that the ancestors of all living Eurasians interbred with the Neandertals, while past Asians/Oceanians also mated with the mysterious ancient humans from Denisova cave in Siberia. This is clear and independent validation of DNA work on both these extinct humans, confirming today’s other big announcement about their deep connections to Australians and other indigenous people in our region.”
Professor Maciej Henneberg is the Wood Jones Professor of Anthropological and Comparative Anatomy at The University of Adelaide’s Medical School.
“This paper by Rasmussen and colleagues suffers from same problems as the one [the American Journal of Human Genetics article]. The sample size of one (N=1) for an Aboriginal Australian hair provides the entire basis for the analyses and discussions in this paper. Moreover, this sample yielded highly fragmented DNA which indicates high level of its degradation. Thus the Authors have at their disposal a single genome that is to a large extent reconstructed from degraded fragments. ”
“The Authors admit this limitation, but then proceed to produce a grandiose discussion on the peopling of Asia and Australia making pronouncements on the number of migration waves and links to Denisovans and Neandertals. Yet again, the directional forces of evolution are ignored (mutation and natural selection) and the analyses are couched in terms of only migration and isolation of populations as if evolution did not take place. Comparing genomes possibly separated by some 60 thousand years, as the Authors admit, would have to consider that mutations and natural selection may have altered genetic material.
“It stands to reason without any analysis that continents, including Australia, were not settled by one wave of migration over tens of thousands of years. Archaeological record and historical information indicate that people move all the time and get to new places settling there or mixing with locals. What is new about it?
“Models considered in this paper are very simplistic.
“The paper may be showing off technical prowess of Authors at genetic analyses, but intellectually it adds very little to our understanding of the peopling of Australia.”
Video credits: Voice: Sheena Lauersen. Illustration: Science/AAAS, Sofia Olsen. Stills: Mikal Schlosser, Timothy P. Topper. Camera: Kristoffer Aabo, Henrik Prætorius. Production: Henrik Prætorius.