Data from: Computer simulations show that Neanderthal facial morphology represents adaptation to cold and high energy demands, but not heavy biting

Three adaptive hypotheses have been forwarded to explain the distinctive Neanderthal face: 1) an improved ability to accommodate high anterior bite forces, 2) more effective conditioning of cold and/or dry air, and, 3) adaptation to facilitate greater ventilatory demands. We test these hypotheses using three-dimensional models of Neanderthals, modern humans, and a close outgroup (H. heidelbergensis), applying finite element analysis (FEA) and computational fluid dynamics (CFD). This is the most comprehensive application of either approach applied to date and the first to include both. FEA reveals few differences between H. heidelbergensis, modern humans and Neanderthals in their capacities to sustain high anterior tooth loadings. CFD shows that the nasal cavities of Neanderthals and especially modern humans condition air more efficiently than does that of H. heidelbergensis, suggesting that both evolved to better withstand cold and/or dry climates than less derived Homo. We further find that Neanderthals could move considerably more air through the nasal pathway than could H. heidelbergensis or modern humans, consistent with the propositions that, relative to our outgroup Homo, Neanderthal facial morphology evolved to reflect improved capacities to better condition cold, dry air, and, to move greater air volumes in response to higher energetic requirements.

已有三项适应性假说被提出，用以解释尼安德特人（Neanderthal）面部的独特形态特征：1. 提升了承受较高前牙咬合力的能力；2. 对寒冷或干燥空气具备更高效的温湿度调节能力；3. 为满足更高通气需求而演化出的适应性特征。本研究借助涵盖尼安德特人、现代人类以及近缘外类群海德堡人（H. heidelbergensis）的三维模型，采用有限元分析（FEA）与计算流体动力学（CFD）两种方法对上述假说进行验证。本研究是目前为止对这两种方法各自最全面的应用，同时也是首次将二者结合使用的同类研究。有限元分析结果显示，海德堡人、现代人类与尼安德特人在承受前牙高负荷载荷的能力上几乎无显著差异。计算流体动力学结果表明，尼安德特人，尤其是现代人类的鼻腔对空气的调节效率高于海德堡人，这意味着二者相较于演化程度更低的人属物种，更能适应寒冷或干燥的气候环境。本研究还发现，尼安德特人通过鼻腔通路输送的空气量显著高于海德堡人与现代人类，这与以下假说相符：相较于作为外类群的海德堡人，尼安德特人的面部形态演化实则是为了优化对寒冷干燥空气的调节能力，并满足更高能量代谢需求所需的更大通气量。