División Antropología, Museo de La Plata, Universidad Nacional de La Plata, Paseo del Bosque s/n 1900, La Plata, Argentina.
Proc Biol Sci. 2010 Apr 7;277(1684):1107-12. doi: 10.1098/rspb.2009.1823. Epub 2009 Dec 2.
The knowledge of processes involved in morphological variation requires the integrated analysis of evolutionary and ecological factors. Here, we investigate the factors responsible for dental variation among human populations from southern South America. The aim of this work is to test the correspondence of dental size and shape variation with geographical, molecular (i.e. mtDNA) and ecological (i.e. climate, diet and food preparation) variables employing comparative phylogenetic methods, which have not previously been extensively applied at a within-species level. The results of the Procrustes analysis show a significant association of shape variables with molecular distance and geography, whereas dental size is not associated with molecular or geographical distances among groups. Phylogenetic generalized least-squares analysis, which takes into account the evolutionary autocorrelation among populations, shows a significant relationship between dental size variation and diet, while temperature and pottery do not correspond with dental size or shape. Specifically, groups with diets rich in carbohydrates, as well as the maritime hunter-gatherers, have the smallest teeth. In summary, our results support ecological factors as the dominant factor on dental size diversification in this region, while evolutionary relationships account for variation in dental shape.
形态变异过程的知识需要综合分析进化和生态因素。在这里，我们调查了来自南美洲南部的人类群体中牙齿变异的原因。这项工作的目的是通过比较系统发育方法来检验牙齿大小和形状变异与地理、分子（即 mtDNA）和生态（即气候、饮食和食物准备）变量之间的一致性，这些方法以前在种内水平上没有得到广泛应用。Procrustes 分析的结果表明，形状变量与分子距离和地理之间存在显著的相关性，而牙齿大小与群体之间的分子或地理距离没有相关性。考虑到群体之间的进化自相关性的系统发育广义最小二乘分析表明，牙齿大小的变化与饮食之间存在显著的关系，而温度和陶器与牙齿大小或形状无关。具体来说，饮食中富含碳水化合物的群体以及沿海狩猎采集者的牙齿最小。总之，我们的结果支持生态因素是该地区牙齿大小多样化的主要因素，而进化关系则解释了牙齿形状的变异。
