de Azevedo Soledad, Bortolini Maria C, Bonatto Sandro L, Hünemeier Tábita, Santos Fabrício R, González-José Rolando
Centro Nacional Patagónico, Consejo Nacional de Investigaciones Científicas y Técnicas, Bvd. Brown 2915, U9120ACD, Puerto Madryn, Argentina.
Departamento de Genética, Instituto de Biociências, Universidade Federal do Rio Grande do Sul, 91501-970, Porto Alegre, RS, Brazil.
Am J Phys Anthropol. 2015 Nov;158(3):514-21. doi: 10.1002/ajpa.22801. Epub 2015 Jul 14.
A noticeably well-preserved ∼12.500 years-old skeleton from the Hoyo Negro cave, Yucatán, México, was recently reported, along with its archaeological, genetic and skeletal characteristics. Based exclusively on an anatomical description of the skull (HN5/48), Chatters and colleagues stated that this specimen can be assigned to a set of ancient remains that differ from modern Native Americans, the so called "Paleoamericans". Here, we aim to further explore the morphological affinities of this specimen with a set of comparative cranial samples covering ancient and modern periods from Asia and the Americas.
Images published in the original article were analyzed using geometric morphometrics methods. Shape variables were used to perform Principal Component and Discriminant analysis against the reference samples.
Even thought the Principal Component Analysis suggests that the Hoyo Negro skull falls in a subregion of the morphospace occupied by both "Paleoamericans" and some modern Native Americans, the Discriminant analyses suggest greater affinity with a modern Native American sample.
These results reinforce the idea that the original population that first occupied the New World carried high levels of within-group variation, which we have suggested previously on a synthetic model for the settlement of the Americas. Our results also highlight the importance of developing formal classificatory test before deriving settlement hypothesis purely based on macroscopic descriptions.
最近报道了一具来自墨西哥尤卡坦州霍约内格罗洞穴的保存异常完好、距今约12500年的骨骼及其考古、基因和骨骼特征。Chatters及其同事仅根据对头骨(HN5/48)的解剖学描述指出,该标本可归为一组与现代美洲原住民不同的古代遗骸,即所谓的“古美洲人”。在此,我们旨在通过一组涵盖亚洲和美洲古代及现代时期的比较颅骨样本,进一步探究该标本的形态学亲缘关系。
使用几何形态测量学方法分析原始文章中发表的图像。利用形状变量对参考样本进行主成分分析和判别分析。
尽管主成分分析表明霍约内格罗头骨位于“古美洲人”和一些现代美洲原住民所占据的形态空间子区域内,但判别分析表明它与一个现代美洲原住民样本的亲缘关系更强。
这些结果强化了这样一种观点,即最早占据新大陆的原始人群内部存在高度的变异,这是我们之前在美洲定居的综合模型中所提出的。我们的结果还强调了在单纯基于宏观描述得出定居假说之前,开展正式分类测试的重要性。