American Journal of Physical Anthropology doi:10.1002/ajpa.21332
Regional shape change in adult facial bone curvature with age
Shanna E. Williams, Dennis E. Slice
Life expectancies have increased dramatically over the last 100 years, affording greater opportunities to study the impact of age on adult craniofacial morphology. This article employs a novel application of established geometric morphometric methods to examine shape differences in adult regional facial bone curvature with age. Three-dimensional semilandmarks representing the curvature of the orbits, zygomatic arches, nasal aperture, and maxillary alveolar process were collected from a cross-sectional cranial sample of mixed sex and ancestry (male and female; African- and European-American), partitioned into three age groups (young adult = 18-39; middle-aged = 40-59 years; and elderly = 60+ years). Each facial region's semilandmarks were aligned into a common coordinate system via generalized Procrustes superimposition. Regional variation in shape was then explored via a battery of multivariate statistical techniques. Age-related shape differences were detected in the orbits, zygomatic arches, and maxillary alveolar process. Interactions between age, sex, and ancestry were also identified. Vector plots revealed patterns of superoinferior compression, lateral expansion, and posterior recession depending on the population/subpopulation, location, and age groups examined. These findings indicate that adult craniofacial curvature shape is not static throughout human life. Instead, age-related spatial modifications occur in various regions of the craniofacial skeleton. Moreover, these regional alterations vary not only through time, but across human populations and the sexes.
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I didn't read the paper, but how do they know the changes are not due to dietary changes over the past 40 years?
ReplyDeletegood point bro!
ReplyDeleteI didn't read it either but I'm wondering if men stay more attractive as they age as they still mate. might help explain why women go for older guys but men don't go for older women.
It's unfortunate that the Iranian sample, probably, included ethnic Turkomen, Balochis, and Iranian arabs (throughout coastal Iran and Kuzestan). Y-DNA data, suggests that the relatively high South Asian component, is restricted to the strip along the south of the plateau, where there is a presence of Dravidoid-specific haplogroups. The Mongoloid component, can largely be attributed to ethnic Turkomen.
ReplyDeleteThe individual samples show a fair degree of heterogenity, and suggest that while, overall, Iranians are generally an extension of Turkic and Caucasian groups, there are clear Outliers among their people.