The 82nd Annual Meeting of the American Association of Physical Anthropologists (2013)


Quantitative Genetic Analysis of Morphometric Data: Challenges and Considerations

RICHARD J. SHERWOOD1,2,3, KIERAN P. MCNULTY4 and DANA L. DUREN1,5.

1Department of Community Health, Wright State University, 2Department of Pediatrics, Wright State University, 3Department of Orthodontics, Case Western Reserve University, 4Evolutionary Anthropology Lab, University of Minnesota, 5Department of Orthopaedic Surgery, Wright State University

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The characterization and quantification of craniofacial form has long been a primary interest of comparative anatomists. While modern morphometric techniques are proving very successful at describing craniofacial shape, the dissection of the genetic determinants of that shape is more elusive. The current research seeks to elucidate the genetic underpinnings of variation in the complex craniofacial and dentognathic regions.

When approaching the genetic analysis of a complex shape, consideration must be given to the mode of acquisition of phenotypic characters with the ultimate goal of the genetic analyses. While simple methodologies may provide only a cursory description of shape compared to more sophisticated geometric techniques, the former may outperform the latter in elucidating the genetic underpinnings influencing trait variation. Comparisons of differing morphometric techniques, and their relative power in subsequent quantitative genetic analyses, illustrate the challenges encountered when trying to maximize the strength of both the morphologic descriptors and the genetic signal.

If the primary goal of statistical genetic analyses is to identify the genes influencing variation, the likelihood of achieving that goal is related to the number of genes involved and the effect size of those genes. It is typically more difficult to localize and identify the genetic influences of polygenic traits because each gene, by itself, may exert a relatively small influence. With proper consideration, the goals of both the maximal description of biological shape, and the dissection of the genetic architecture influencing that shape, can be accomplished.

This work is supported by the National Institute of Dental and Craniofacial Research DE018497, DE016692, DE016408.

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