Individual Identifiability Predicts Population Identifiability in Forensic Microsatellite Markers

Area of Science:

• Forensic genetics
• Population genetics
• Human genetics

Background:

• Highly polymorphic genetic markers are crucial for forensic identification.
• These markers also contain information about genetic ancestry.
• The potential for dual use in forensics and ancestry inference is significant.

Purpose of the Study:

• To investigate if forensic marker sets, specifically the 13 CODIS loci, provide substantial genetic ancestry information.
• To determine the relationship between individual identifiability and population identifiability using genetic markers.

Main Methods:

• Studied the 13 CODIS loci and 779 additional microsatellites.
• Employed direct population structure inference methods.
• Analyzed marker polymorphism, heterozygosity, and F(ST) statistics.

Main Results:

• The CODIS markers, despite selection for individual identification, showed nontrivial population clustering.
• High heterozygosity in forensic markers contributed to greater ancestry inference potential than less heterozygous sets.
• A general trend observed: greater individual identifiability correlates with greater population identifiability.

Conclusions:

• Population identifiability is a common byproduct of using highly polymorphic forensic markers.
• Findings impact the design of future forensic marker sets.
• Forensic data may offer insights beyond individual identification, including population characteristics.