Population Identifiability from Forensic Genetic Markers: Ancestry Variation in Latin America

The Combined DNA Index System (CODIS) loci comprise a standard microsatellite marker set widely used for distinguishing among individuals in forensic identity testing medicolegal casework the United States and other countries. In anthropological genetic research, CODIS markers have become an important tool uses extending beyond case investigations to quantify ancestry proportions, reveals patterns of admixture, trace population histories. These are especially prevalent studies Latin American structure. Nevertheless, accuracy estimates computed from highly admixed Latino populations has not been formally tested. Longstanding arguments made that small panels, including specifically, suitable inference populations, due high heterozygosity limited number used. Recent on using suggest these do confer more information population-level identifiability than recognized scholarship by community. Here, we test ability CODIS-proxy (e.g., high-heterozygosity individual-identifiability loci) panels accurately estimate admixture proportions individuals, sample Latinos with wide range proportions. Using same make direct comparisons outcomes, authors produced (a) CODIS/CODIS-proxy locus panel (b) robust validated ancestry-informative panel. They found evidence ρ = 0.80–0.88) supports use CODIS/ capture general estimation trends sample. This finding is line results populations: estimations generated present supported documented histories colonialism movements) microevolutionary events gene flow) America. However, this study also highlights limitations making individual-level inferences ancestry: associated acceptable level statistical confidence (95%) too broad any nuanced regarding individual’s actual composition.