Craniofacial variation, body size and ecologicalfactors in aboriginal populations from centralPatagonia (2000?200 years B.P.)

BERNAL, VALERIA; BEGUELIN, MARIEN; GORDÓN, FLORENCIA; COBOS, VIRGINIA; GONZÁLEZ, PAULA; LOTTO, FEDERICO

Homo - Journal of Comparative Human Biology

Elsevier

Año: 2014 vol. 65 p. 101 - 114

0018-442X

tPrevious studies have shown that ecological factors had a signifi-cant role in shaping the patterns of craniofacial variation amongSouth American populations. Here, we evaluate whether tem-perature and diet contributed to facial diversification in smallgeographic areas. Facial size and shape of 9 osteological samplesfrom central Patagonia (Argentina) were described using 2D land-marks and semilandmarks. Data on mean annual temperature, dietcomposition (13C and 15N values) and femoral head maximumbreadth, used as a proxy of body mass, were obtained for eachsample. We then tested the association of body mass and the eco-logical variables with facial morphology using spatial regressiontechniques and a model selection approach. Akaike InformationCriterion produced disparate results for both components of facialmorphology. The best model for facial size included temperatureand body mass proxy, and accounted for more than 80% of varia-tion in size. Lower temperatures were related to larger facial sizes.Body mass was negatively associated with facial size and showed norelationship with the temperature. This suggests a relatively inde-pendent variation of cranial traits and body mass at the spatial scale studied here. Facial shape was not associated with the tempera-ture or diet composition, contrasting with the patterns observedat larger spatial scales. Our results point out that the effect of cli-matic variables on cranial traits might be a source of morphologicaldifferentiation not only at large scales but also in small geographicareas, and that size and shape display a differential preservation ofenvironmental signals.