Hubbe Mark, Strauss André, Hubbe Alex, Neves Walter A
Department of Anthropology, The Ohio State University, Columbus, Ohio, United States of America; Instituto de Investigaciones Arqueológicas y Museo, Universidad Católica del Norte, San Pedro de Atacama, Región de Antofagasta, Chile.
Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.
PLoS One. 2015 Oct 14;10(10):e0138090. doi: 10.1371/journal.pone.0138090. eCollection 2015.
Recent South Americans have been described as presenting high regional cranial morphological diversity when compared to other regions of the world. This high diversity is in accordance with linguistic and some of the molecular data currently available for the continent, but the origin of this diversity has not been satisfactorily explained yet. Here we explore if this high morphological variation was already present among early groups in South America, in order to refine our knowledge about the timing and origins of the modern morphological diversity. Between-group (Fst estimates) and within-group variances (trace of within-group covariance matrix) of the only two early American population samples available to date (Lagoa Santa and Sabana de Bogotá) were estimated based on linear craniometric measurements and compared to modern human cranial series representing six regions of the world, including the Americas. The results show that early Americans present moderate within-group diversity, falling well within the range of modern human groups, despite representing almost three thousand years of human occupation. The between-group variance apportionment is very low between early Americans, but is high among recent South American groups, who show values similar to the ones observed on a global scale. Although limited to only two early South American series, these results suggest that the high morphological diversity of native South Americans was not present among the first human groups arriving in the continent and must have originated during the Middle Holocene, possibly due to the arrival of new morphological diversity coming from Asia during the Holocene.
与世界其他地区相比，近代南美洲人呈现出高度的区域颅骨形态多样性。这种高度多样性与目前该大陆可得的语言和一些分子数据相一致，但这种多样性的起源尚未得到令人满意的解释。在这里，我们探究这种高度的形态变异在南美洲早期群体中是否已然存在，以便完善我们对现代形态多样性的时间和起源的认识。基于线性颅骨测量，对迄今仅有的两个早期美洲人群样本（拉戈阿圣塔和波哥大萨瓦纳）的组间（Fst估计值）和组内方差（组内协方差矩阵的迹）进行了估计，并与代表世界六个地区（包括美洲）的现代人类颅骨系列进行了比较。结果表明，尽管早期美洲人代表了近三千年的人类居住历史，但他们的组内多样性适中，完全处于现代人类群体的范围内。早期美洲人之间的组间方差分配非常低，但在近代南美洲群体中则很高，这些群体显示出与全球范围内观察到的值相似的数值。尽管仅限于仅有的两个早期南美洲系列，但这些结果表明，南美洲原住民的高度形态多样性在首批抵达该大陆的人类群体中并不存在，而且肯定起源于中全新世，可能是由于全新世期间来自亚洲的新形态多样性的到来。
