Shifts in Subsistence Type and Its Impact on the Human Skull's Morphological Integration

PASCHETTA, C.A.; DE AZEVEDO, S.; GONZÁLEZ, M.F.; QUINTO-SANCHEZ, M.; CINTAS, C.; VARELA, H.H.; GÓMEZ-VALDES, J.; SANCHEZ-MEJORADA, G.; GONZÁLEZ JOSÉ, R.

AMERICAN JOURNAL OF HUMAN BIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2016 vol. 28 p. 118 - 128

1042-0533

Objective: Here we evaluate morphological integration patterns and magnitudes in different skull regions to detectif shifts in morphological integration are correlated to the appearance of more processed (softer) diets.Methods: To do so, three transitional populations were analyzed, including samples from groups that inhabited thesame geographical region and for which the evidence shows that major changes occurred in their subsistence mode.Ninety three-dimensional landmarks were digitized on 357 skulls and used as the raw data to develop geometric morphometricanalyses. The landmark coordinates were divided into several different regions of biomechanical interest,following a three-level hierarchically nested scheme: the whole skull, further subdivided into neurocranium (dividedinto the vault and basicranium), the facial (divided into the lower and upper facial), and the masticatory apparatus(divided into alveolar, temporal, and temporo-mandibular joint).Results: Our results indicate that the morphological integration and variability patterns significantly vary acrossskull regions but are maintained across the transitions. The alveolar border and the lower facial are the regions manifestinggreater value of morphological integration and variability, while the upper facial, the temporo-mandibular joint,and the basicranium are highly integrated and poorly variable.Conclusions: The transition to softer diets increased morphological variation across cranial regions that are moreexposed to masticatory strains effects.