Validating Foundational Assumptions of Dental Morphology Using Quantitative Genetics
Document Type
Presentation
Publication Date
3-29-2019
Description
Presented in the session “Global Leadership in Dental Anthropological Research: A symposium in honor of G. Richard Scott." The Arizona State University Dental Anthropology System (ASUDAS) or Turner-Scott System revolutionized the use of dental morphology for reconstructing evolutionary processes in past populations. By providing globally-recognized data collection standards, the system has elevated the status of dental morphology to an indispensable line of evidence in biodistance research. The efficacy of morphological data rests upon foundational assumptions about underlying tooth crown biology; namely, that the traits are highly heritable and minimally sexually dimorphic. Scott and colleagues have also outlined best practices for the application of dental morphology to biodistance studies, most aimed at curtailing genetic redundancy in multivariate datasets (see Turner et al., 1991). Quantitative genetic approaches have the potential to validate these assumptions. Here, we present the first robust estimates of heritability and genetic correlation for ASUDAS crown characters. Data were collected from a casted sample of South Carolina Gullah individuals (N=469) and analyzed using maximum likelihood variance components analysis. While several postcanine traits yielded heritability estimates of 0.0, mean estimates across statistically significant models were moderate to high (anterior=0.34; postcanine=0.75). Results of covariate screening support the long-held assumption that ASUDAS traits are sexually monomorphic, with the exception of canine marginal/cingular ridge characters and certain molar accessory cusps. Additionally, patterns of heritability and genetic correlation groundtruth most prescribed biodistance practices: dichotomizing trait expression, collapsing bi-antimeric datasets, and prioritizing traits scored on key (sensu Scott et al., 2018) teeth. Notwithstanding, our results suggest that certain assumptions require reconsideration and underscore the importance of continued validation work in additional populations.
Location
Cleveland, OH
Citation Information
Paul, Kathleen; Stojanowski, Christopher; Duncan, William N.; and Johnson, Kent. 2019. Validating Foundational Assumptions of Dental Morphology Using Quantitative Genetics. Poster Presentation. 88th Annual Meeting of the American Association of Physical Anthropologists, Cleveland, OH. https://meeting.physanth.org/program/2019/session37/paul-2019-validating-foundational-assumptions-of-dental-morphology-using-quantitative-genetics.html