Sardi Marina L, Novellino Paula S, Pucciarelli Héctor M
Departamento Científico de Antropología, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, 1900 La Plata, Argentina.
Am J Phys Anthropol. 2006 Jul;130(3):333-43. doi: 10.1002/ajpa.20379.
The Argentine Center-West was the southernmost portion of the Andes where domestication of plants and animals evolved. Populations located in the southern portion of this area displayed a hunter-gatherer subsistence economy up to historical times, and coexisted with farmers located to the north. Archaeological and biological evidence suggests that the transition to food production was associated with the consumption of a softer diet and a more sedentary way of life. This study tests the hypothesis that diet-related factors influenced morphological differentiation, by comparing functional cranial components of farmers and hunter-gatherers. Three-dimensional changes on eight minor functional components (anteroneural, midneural, posteroneural, otic, optic, respiratory, masticatory, and alveolar) were measured on skulls derived from both subareas. Volumetric and morphometric indices were calculated to estimate the absolute and relative size of components, respectively. Results of a paired t-test indicated that farmers have a smaller craniofacial size than hunter-gatherers. The components that varied the most were masticatory and posteroneural, showing smaller absolute and relative sizes in farmers. Discriminant analyses indicated that lengths and widths were the most affected dimensions of these and other components. The pattern of differentiation, which involves specific components, enabled us to exclude differential gene flow and stochastic mechanisms as the main causes. Instead, results support the hypothesis that diet-related factors associated with both subsistence economies influenced craniofacial morphology. A proportion of the observed variation associated with size differences can be explained by two systemic factors: the lesser quality of nutrition due to a low protein content in the diet, and a decrease of growth hormone circulation induced by a lower mobility due to sedentism. However, differentiation is better explained by a localized factor: the reduction in the masticatory and posteroneural components in farmers resulted from a decrease of masticatory stresses and workload on the head and neck, linked to the consumption of a softer diet.
阿根廷中西部地区是安第斯山脉最南端的区域，动植物驯化在此得以发展。直至历史时期，该地区南部的人群仍维持着狩猎采集的生存经济，并与北部的农民群体共存。考古学和生物学证据表明，向食物生产的转变与更柔软的饮食结构以及更定居的生活方式有关。本研究通过比较农民和狩猎采集者的功能性颅骨成分，来检验饮食相关因素影响形态分化这一假设。在来自两个子区域的头骨上，测量了八个次要功能成分（前神经、中神经、后神经、耳部、视觉、呼吸、咀嚼和牙槽）的三维变化。计算了体积和形态测量指标，分别用以估计各成分的绝对大小和相对大小。配对t检验结果表明，农民的颅面尺寸比狩猎采集者小。变化最大的成分是咀嚼和后神经成分，在农民中显示出更小的绝对大小和相对大小。判别分析表明，长度和宽度是这些成分及其他成分受影响最大的维度。这种涉及特定成分的分化模式，使我们能够排除差异基因流动和随机机制作为主要原因。相反，结果支持了这样的假设，即与两种生存经济相关的饮食因素影响了颅面形态。观察到的与大小差异相关的一部分变异，可以由两个系统因素来解释：由于饮食中蛋白质含量低导致营养质量较差，以及由于定居生活导致活动减少而引起的生长激素循环减少。然而，分化更好地由一个局部因素来解释：农民咀嚼和后神经成分的减少，是由于咀嚼压力以及头部和颈部工作量的减少，这与更柔软的饮食摄入有关。
