INVESTIGADORES
GONZALEZ paula Natalia
artículos
Título:
Geographic variation, diet and temperature in cranial morphology of South American human populations: an approach based on spatial regression and rate tests
Autor/es:
PEREZ S.I.; LEMA V.; FELIZOLA DINIZ-FILHO JA; BERNAL V.; GONZALEZ P.; GOBBO D.; PUCCIARELLI H.
Revista:
JOURNAL OF BIOGEOGRAPHY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2011 vol. 38 p. 148 - 163
ISSN:
0305-0270
Resumen:
Aim
Understanding the importance of ecological factors in the origin and
maintenance of patterns of phenotypic variation among populations, in an
explicit geographical context, is one of the main goals of human
biology, ecology and evolutionary biology. Here we study the ecological
factors responsible for craniofacial variation among human populations
from South America.
Location South America.
Methods
We studied a dataset of 718 males from 40 South American populations,
coming from groups that inhabited different geographical and ecological
regions. Cranial size and shape variation were studied using 30 cranial
measurements. We first used spatial correlograms and interpolated maps
to address spatial patterns. We then regressed the shape (principal
component scores) and size variables against ecology (mean annual
temperature and diet) using multiple and multivariate spatial
regression. Finally, the expected magnitudes of shape and size
divergence under the influence of genetic drift and mutations alone were
evaluated using neutral expectation for the divergence rate.
Results
The spatial correlograms showed a cline affecting the entire South
American distribution. Interpolated maps showed that size and allometric
shape vary from south-east to north-west. Multiple and multivariate
regression analyses suggested that diet has the largest and most
significant effect on this pattern of size and allometric shape
variation. Finally, the results of the divergence rate test suggested
that random processes alone cannot account for the morphological
divergence exhibited by cranial size and allometric shape scores among
southernmost populations.
Main conclusions
Correlograms, spatial regression and divergence rate analyses showed
that although local factors (neutral processes or local environmental
conditions) are important to explain spatial interpopulation
differentiation in cranial characteristics among these populations,
there is significant correlation of cranial size and allometric shape
variation with diet. Gene flow among human populations, or local
environmental conditions, could explain spatial variation mainly at
smaller spatial scales, whereas the large-scale pattern of the South
American dataset is mainly related to the high proportion of
carbohydrates and low proportion of proteins consumed.