Variation in dental morphology and inference of continental ancestry in admixed Latin Americans

Miguel Delgado (1) , Luis Miguel Ramírez (2) , Kaustubh Adhikari (3) , Macarena Fuentes-Guajardo (3, 4) , Clément Zanolli (5) , Rolando González-José (6) , Samuel Canizales (7) , Maria-Catira Bortolini (8) , Giovanni Poletti (9) , Carla Gallo (9) , Francisco Rothhammer (4, 10) , Gabriel Bedoya (2) , Andrés Ruiz-Linares (11, 12)

1 UPC - Universitat Politècnica de Catalunya = Université polytechnique de Catalogne [Barcelona]
2 Universidad de Antioquia = University of Antioquia [Medellín, Colombia]
3 UCL - University College of London [London]
4 Universidad de Tarapaca
5 PACEA - De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie
6 CONICET - Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires]
7 UNAM - Universidad Nacional Autónoma de México = National Autonomous University of Mexico
8 UFRGS - Universidade Federal do Rio Grande do Sul [Porto Alegre]
9 UPCH - Universidad Peruana Cayetano Heredia
10 UCHILE - Universidad de Chile = University of Chile [Santiago]
11 UCL-GEE - Dept of Genetics, Evolution and Environment [London]
12 ADES - Anthropologie bio-culturelle, Droit, Ethique et Santé

Objectives: To investigate the variation in dental nonmetric traits and to evaluate the utility of this variation for inferring genetic ancestry proportions in a sample of admixed Latin Americans. Materials and Methods: We characterized a sample from Colombia (N = 477) for 34 dental traits and obtained estimates of individual Native American, European, and African ancestry using genome‐wide SNP data. We tested for correlation between dental traits, genetic ancestry, age, and sex. We carried out a biodistance analysis between the Colombian sample and reference continental population samples using the mean measure of divergence statistic calculated from dental trait frequencies. We evaluated the inference of genetic ancestry from dental traits using a regression approach (with 10‐fold cross‐validation) as well as by testing the correlation between estimates of ancestry obtained from genetic and dental data. Results: Latin Americans show intermediate dental trait frequencies when compared to Native Americans, Europeans, and Africans. Significant correlations were observed for several dental traits, genetic ancestry, age, and sex. The biodistance analysis displayed a closer relationship of Colombians to Europeans than to Native Americans and Africans. Mean ancestry estimates obtained from the dental data are similar to the genetic estimates (Native American: 32% vs. 28%, European: 59% vs. 63%, and African: 9% vs. 9%, respectively). However, dental features provided low predictive power for genetic ancestry of individuals in both approaches tested (R2 < 5% for all genetic ancestries across methods). Discussion: The frequency of dental traits in Latin Americans reflects their admixed Native American, European and African ancestry and can provide reasonable average estimates of genetic ancestry. However, the accuracy of individual genetic ancestry estimates is relatively low, probably influenced by the continental differentiation of dental traits, their genetic architecture, and the distribution of genetic ancestry in the individuals examined.

Mots clés: dental morphology; admixture; ancestry inference; Latin America

Domaines: Anthropologie biologique

Miguel Delgado, Luis Miguel Ramírez, Kaustubh Adhikari, Macarena Fuentes-Guajardo, Clément Zanolli, et al.. Variation in dental morphology and inference of continental ancestry in admixed Latin Americans. American Journal of Physical Anthropology, 2019, 168 (3), pp.438-447. ⟨10.1002/ajpa.23756⟩. ⟨hal-02296715⟩