Indigenous Australian genomes show deep structure and rich novel variation

Area of Science:

• Population Genetics
• Genomics
• Anthropology

Background:

• Indigenous Australians possess rich linguistic and cultural histories, yet their genetic diversity is underrepresented in genomic studies.
• Limited engagement in genomic research has left the relationship between Indigenous Australian genetics and their history largely unexplored.

Purpose of the Study:

• To analyze the genomes of 159 individuals from four remote Indigenous Australian communities to understand their genetic diversity.
• To investigate the demographic history and population structure of Indigenous Australians and its implications for genomic medicine.

Main Methods:

• Genomic analysis of 159 individuals from four remote Indigenous Australian communities.
• Comparative analysis with global genomic datasets and reference panels.
• Examination of population structure, divergence times, and effective population sizes.

Main Results:

• Observed exceptionally strong population structure across Australia, with divergence times between 26,000-35,000 years ago.
• Found the highest proportion of previously undescribed genetic variation outside Africa and extended homozygosity compared to global samples.
• Identified a substantial proportion of unique genetic variation, with functionally significant variants more likely to be homozygous, impacting medical genomics.

Conclusions:

• Indigenous Australians are genetically diverse, not a homogeneous group, with non-uniform genetic relationships to Papua New Guinean populations.
• The unique genetic patterns have implications for medical genomics, potentially limiting equitable healthcare.
• Further genomic research is needed to characterize the full breadth of Indigenous Australian genetic diversity.