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Deep Roots for Aboriginal Australian Y Chromosomes.
Anders Bergström1, Nano Nagle2, Yuan Chen1
1The Wellcome Trust Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK.
Current Biology : CB
|March 1, 2016
Summary
New genetic analysis of Aboriginal Australian Y chromosomes indicates they diverged around 50,000 years ago, refuting recent gene flow from India. This finding impacts our understanding of early human migration and population genetics in Australia.
Area of Science:
- Human Origins
- Population Genetics
- Archaeogenetics
Background:
- Australia was colonized by modern humans by 47,000 years ago.
- Subsequent human migration into Australia before European colonization is less understood.
- Previous studies suggested gene flow from India to Australia around 5,000 years ago based on genetic data.
Purpose of the Study:
- To re-investigate Y chromosome divergence times in Aboriginal Australians.
- To compare Aboriginal Australian and South Asian Y chromosome haplogroup C.
- To assess evidence for recent gene flow from the Indian subcontinent to Australia.
Main Methods:
- Sequencing of 13 Aboriginal Australian Y chromosomes.
- Divergence time estimation of Y chromosomes from different continents.
- Comparative analysis of haplogroup C chromosomes between Aboriginal Australians and South Asians.
Main Results:
- Y chromosome divergence times were estimated to be around 50,000 years ago.
- This divergence predates the proposed timeframe for gene flow from India.
- Haplogroup C analysis did not support recent migration from India.
Conclusions:
- The Y chromosome does not provide evidence for recent gene flow from India into Australia.
- Early human migration into Australia occurred significantly earlier than previously suggested by some genetic data.
- This study refines the timeline of human settlement and genetic history in Australia.
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