Department of Anatomical Sciences, Stony Brook University Medical Center, NY 11794, USA.
J Hum Evol. 2009 Nov;57(5):608-22. doi: 10.1016/j.jhevol.2008.08.011. Epub 2008 Dec 4.
The unique set of morphological characteristics of the Liang Bua hominins (Homo floresiensis) has been attributed to explanations as diverse as insular dwarfism and pathological microcephaly. This study examined the relationship between cranial size and shape across a range of hominin and African ape species to test whether or not cranial morphology of LB1 is consistent with the basic pattern of static allometry present in these various taxa. Correlations between size and 3D cranial shape were explored using principal components analysis in shape space and in Procrustes form space. Additionally, patterns of static allometry within both modern humans and Plio-Pleistocene hominins were used to simulate the expected cranial shapes of each group at the size of LB1. These hypothetical specimens were compared to LB1 both visually and statistically. Results of most analyses indicated that LB1 best fits predictions for a small specimen of fossil Homo but not for a small modern human. This was especially true for analyses of neurocranial landmarks. Results from the whole cranium were less clear about the specific affinities of LB1, but, importantly, demonstrated that aspects of facial morphology associated with smaller size converge on modern human morphology. This suggests that facial similarities between LB1 and anatomically modern humans may not be indicative of a close relationship. Landmark data collected from this study were also used to test the degree of cranial asymmetry in LB1. These comparisons indicated that the cranium is fairly asymmetrical, but within the range of asymmetry exhibited by modern humans and all extant African ape species. Compared to other fossil specimens, the degree of asymmetry in LB1 is moderate and readily explained by the taphonomic processes to which all fossils are subject. Taken together, these findings suggest that H. floresiensis was most likely the diminutive descendant of a species of archaic Homo, although the details of this evolutionary history remain obscure.
梁布亚古人类（弗洛勒斯人）独特的形态特征被归因于多种解释，包括岛屿侏儒症和病理性小头症。本研究考察了一系列人属和非洲猿物种之间颅大小和形状的关系，以检验 LB1 的颅形态是否与这些不同分类群中存在的静态比例关系的基本模式一致。在形状空间和 Procrustes 形式空间中，使用主成分分析探索了大小与 3D 颅形状之间的相关性。此外，还利用现代人类和上新世-更新世人属内的静态比例关系，模拟了每组在 LB1 大小下的预期颅形状。这些假设标本在视觉和统计学上都与 LB1 进行了比较。大多数分析的结果表明，LB1 最符合化石 Homo 小标本的预测，但不符合小现代人类的预测。对于神经颅地标分析尤其如此。整个颅骨的分析结果不太清楚 LB1 的具体亲缘关系，但重要的是，表明与较小体型相关的面部形态特征与现代人类形态趋同。这表明 LB1 和解剖学上的现代人类之间的面部相似性可能并不表明它们之间存在密切的关系。本研究收集的地标数据也用于测试 LB1 颅的不对称程度。这些比较表明，颅骨相当不对称，但在现代人类和所有现存的非洲猿物种表现出的不对称范围内。与其他化石标本相比，LB1 的不对称程度适中，很容易用所有化石都经历的埋藏过程来解释。总的来说，这些发现表明，H. floresiensis 很可能是古老 Homo 物种的矮小后代，尽管其进化历史的细节仍不清楚。
