Use of subpopulation data in Australian forensic DNA casework

Area of Science:

• Forensic Science
• Population Genetics
• Genetics

Background:

• Reliable DNA profiling evidence requires accurate allele frequency estimates.
• Autosomal microsatellite loci are commonly used for DNA profiling.
• Current allele frequency datasets are often based on broad bio-geographic categories and jurisdictional administration.

Purpose of the Study:

• To assess the appropriateness of current Australian jurisdictional data practices for DNA profiling.
• To evaluate genetic diversity representation for Aboriginal Australian and Caucasian populations.
• To determine if traditional population groupings are more suitable for forensic genetic analysis.

Main Methods:

• Analysis of autosomal microsatellite loci allele frequencies.
• Comparison of genetic diversity within Australian Caucasian populations across different jurisdictions.
• Examination of genetic diversity within Aboriginal Australian populations segregated by State and Territory lines versus traditional groupings.

Main Results:

• Negligible genetic differences were observed among Caucasian populations within Australia when geographically segregated.
• Segregating Aboriginal Australian population data by State and Territory lines masked significant genetic diversity.
• Traditional population groupings better reflect the genetic differentiation within the Aboriginal Australian population, especially in northern Australia.

Conclusions:

• Current jurisdictional data collection practices in Australia are inadequate for Aboriginal Australian populations.
• Forensic DNA profiling in Australia requires allele frequency datasets that accurately represent the genetic diversity within Aboriginal Australian subpopulations.
• A shift towards traditional population-based data collection is recommended for more accurate and reliable DNA profiling statistics for Aboriginal Australians.