1Anthropology, University of Tennessee, 2Anthropology, University of Tennessee
Thursday Afternoon, 301E
A multitude of research investigating microevolutionary processes has been published that has identified combinations of shape and size related changes in the cranial and postcranial dimensions of modern Americans over time. The majority of these studies have utilized two dimensional data to assess metric differences between 19th and 20th century Americans. However, using geometric morphometrics to examine coordinate data in three dimensions has been shown to aid researchers identify patterns of change within a sample. This study investigates the hypothesis that examining secular change of the cranium in modern American blacks and whites using 3D coordinate data will support previous findings as well as provide better resolution to how variation has changed through time.
This analysis examined coordinate cranial data from American whites and blacks from the University of Tennessee Forensic Databank and the Terry Anatomical collection. Coordinate data was used from 65 landmarks that describe the dimensions of the human cranium. Analyses were carried out using MorphoJ software, which allows for extraction of shape variables to allow for visualization of differences between data sets. Results support the general findings of earlier publications, such as the increase in vault height is mostly due to an inferior lengthening of the cranial base. However, visualization of secular change using 3D coordinates also indicates movement and change of cranial dimensions that have not been previously described, such as anterior movement of the nasomaxillary complex of males and females of the American black samples and inferior displacement in the American white male samples.