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Tooth morphology and population affinity: Testing rASUDAS2 on modern African and European-derived samples

NCJ Number
Date Published
2 pages

This reference details a presentation on the application of rASUDAS, and its modified rASUDAS2, as a methodology for determining human geographic ancestry traits using specific tooth samples. 


The web-based application rASUDAS was first developed from samples and trait frequencies in The Anthropology of Modern Human Teeth. Since 2015, the method has undergone two major modifications. The beta version included 15 crown and 6 root traits. The current version, rASUDAS2, includes four new root traits and seven back-up traits (e.g., if shoveling is not scored on UI1, UI2 expression can be used). Trait frequencies used in the Bayes algorithm were derived from archaeological samples. To test applicability to modern samples, rASUDAS2 was used to calculate posterior probabilities for African and European-derived samples. Based on 12 to 25 traits, every individual has a probability that it can be assigned to one of seven major geno-geographic groups: Western Eurasia, East Asia, American Artic, non-Artic American, Southeast Asian, Australo-Melanesian, and Sub-Saharan Africa. For the modern African sample (n=159), the highest probability of group assignment was 68.6% for Sub-Saharan African and 22.0% for Western Eurasia. Assignments to the remaining five groups were low (0.6-4.4%). For the modern European-derived sample (n=161), Western Eurasia had the highest probability of group assignment (75.2%) followed by Sub-Saharan Africa (13.0%). Samples of mixed African and European ancestry yielded almost identical results of 40% Sub-Saharan and 30% Western Eurasian. Three of four individuals from Africa and Europe can be correctly assigned to their associated ancestral geographic group. For Asians and Europeans, assignment to an Asian or Asian-derived group is unlikely (<10%). (Published Abstract Provided)

Date Published: January 1, 2022