Athreya Sheela, Wu Xinzhi
Department of Anthropology, Texas A&M University, MS 4352 TAMU, College Station, Texas 77843.
Laboratory for Human Evolution, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.
Am J Phys Anthropol. 2017 Dec;164(4):679-701. doi: 10.1002/ajpa.23305. Epub 2017 Oct 25.
A nearly complete hominin fossil cranium from Dali in Shaanxi Province, China was excavated in 1978. We update and expand on previous research by providing a multivariate analysis of the specimen relative to a large sample of Middle and Late Pleistocene hominins.
We apply principal components analysis, discriminant function analysis, and a method of assessing group membership based on a soft independent model of class analogy (SIMCA) to the study of Dali's cranial morphology. We evaluate Dali's affinities within the context of Middle and Late Pleistocene Homo patterns of craniofacial morphology.
When just the facial skeleton is considered, Dali aligns with Middle Paleolithic H. sapiens and is clearly more derived than African or Eurasian Middle Pleistocene Homo. When just the neurocranium is considered, Dali is most similar to African and Eastern Eurasian but not Western European Middle Pleistocene Homo. When both sets of variables are considered together, Dali exhibits a unique morphology that is most closely aligned with the earliest H. sapiens from North Africa and the Levant.
These results add perspective to our previous view of as Dali a "transitional" form between Chinese H. erectus and H. sapiens. Athough no taxonomic allocation is appropriate at this time for Dali, it appears to represent a population that played a more central role in the origin of Chinese H. sapiens. Dali's affinities can be understood in the context of Wu's Continuity with Hybridization scenario and a braided-stream network model of gene flow. Specifically, we propose that Pleistocene populations in China were shaped by periods of isolated evolutionary change within local lineages at certain times, and gene flow between local lineages or between Eastern and Western Eurasia, and Africa at other times, resulting in contributions being made in different capacities to different regions at different times.
1978年在中国陕西省大荔县发掘出一件近乎完整的古人类化石颅骨。我们通过对该标本与大量中更新世和晚更新世古人类样本进行多变量分析,更新并扩展了先前的研究。
我们将主成分分析、判别函数分析以及基于类类比软独立模型(SIMCA)的群体归属评估方法应用于大荔颅骨形态的研究。我们在中更新世和晚更新世智人头面部形态模式的背景下评估大荔的亲缘关系。
仅考虑面部骨骼时,大荔与旧石器时代中期的智人一致,且明显比非洲或欧亚大陆中更新世的直立人更为进化。仅考虑脑颅骨时,大荔与非洲和东亚的中更新世直立人最为相似,但与西欧的不同。当同时考虑两组变量时,大荔呈现出独特的形态,与来自北非和黎凡特的最早智人最为接近。
这些结果为我们之前将大荔视为中国直立人和智人之间“过渡”形式的观点增添了新视角。尽管目前对大荔进行分类归属并不合适,但它似乎代表了一个在中国智人起源中发挥了更核心作用的群体。大荔的亲缘关系可以在吴新智的连续进化附带杂交假说以及基因流辫状河网络模型的背景下得到理解。具体而言,我们认为中国的更新世群体在某些时期受到当地谱系内孤立进化变化的影响,而在其他时期则受到当地谱系之间或欧亚大陆东部和西部以及非洲之间基因流的影响,从而在不同时期以不同能力对不同地区做出贡献。