BACKGROUND Recently we proposed an evolutionary explanation for a spinal pathology that afflicts many people, intervertebral disc herniation (Plomp et al. [2015] BMC Evolutionary Biology 15, 68). Using 2D data, we found that the bodies and pedicles of lower vertebrae of pathological humans were more similar in shape to those of chimpanzees than were those of healthy humans. Based on this, we hypothesized that some individuals are more prone to intervertebral disc herniation because their vertebrae exhibit ancestral traits and therefore are less well adapted for the stresses associated with bipedalism. Here, we report a study in which we tested this "Ancestral Shape Hypothesis" with 3D data from the last two thoracic and first lumbar vertebrae of pathological Homo sapiens, healthy H. sapiens, Pan troglodytes, and several extinct hominins. RESULTS We found that the pathological and healthy H. sapiens vertebrae differed significantly in shape, and that the pathological H. sapiens vertebrae were closer in shape to the P. troglodytes vertebrae than were the healthy H. sapiens vertebrae. Additionally, we found that the pathological human vertebrae were generally more similar in shape to the vertebrae of the extinct hominins than were the healthy H. sapiens vertebrae. These results are consistent with the predictions of the Ancestral Shape Hypothesis. Several vertebral traits were associated with disc herniation, including a vertebral body that is both more circular and more ventrally wedged, relatively short pedicles and laminae, relatively long, more cranio-laterally projecting transverse processes, and relatively long, cranially-oriented spinous processes. We found that there are biomechanical and comparative anatomical reasons for suspecting that all of these traits are capable of predisposing individuals to intervertebral disc herniation. CONCLUSIONS The results of the present study add weight to the hypothesis that intervertebral disc herniation in H. sapiens is connected with vertebral shape. Specifically, they suggest that individuals whose vertebrae are towards the ancestral end of the range of shape variation within H. sapiens have a greater propensity to develop the condition than other individuals. More generally, the study shows that evolutionary thinking has the potential to shed new light on human skeletal pathologies.

中文翻译：

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现存的灵长类动物和化石人猿椎骨的3D形状分析支持了椎间盘突出症的祖先形状假说。

背景技术近来，我们提出了一种折磨许多人的脊椎病理的进化解释，即椎间盘突出症（Plomp et al。[2015] BMC Evolutionary Biology 15，68）。使用2D数据，我们发现病理人类的下椎骨的身体和椎弓根的形状与黑猩猩的相似，而健康人的椎弓根的形状和椎弓根的形状更相似。基于此，我们假设某些人更容易发生椎间盘突出症，因为他们的椎骨具有祖先特征，因此不太适合与两足动物相关的压力。在这里，我们报告了一项研究，其中我们使用了病理性智人，健康智人，盘状穴居人和几种已灭绝的人类素的最后两个胸椎和第一个腰椎的3D数据测试了这种“祖先形状假说”。结果我们发现病理和健康的智人椎体的形状差异很大，并且病理性的智人椎体的形状比健康的智人椎体更接近于穴居人的椎体。此外，我们发现病理性人类椎体的形状通常比健康人猿椎体的形状更接近于灭绝的人类素的椎骨。这些结果与祖先形状假说的预测是一致的。椎间盘突出症伴有多种椎体特征，包括椎体既更圆又楔形，椎弓根和椎板相对较短，相对较长，颅骨侧面突出的横向过程，以及相对较长的颅骨取向的棘突。我们发现存在生物力学和解剖学上的原因，怀疑所有这些特征都可能使个体易患椎间盘突出症。结论本研究的结果增加了假说H.sapiens的椎间盘突出与椎体形状有关的假说。具体而言，他们建议椎骨朝向智人内形状变化范围的祖先端的个体比其他个体更容易患此病。更广泛地说，该研究表明，进化思维有可能为人类骨骼病理学提供新的思路。结论本研究的结果增加了假说H.sapiens的椎间盘突出与椎体形状有关的假说。具体而言，他们建议椎骨朝向智人内形状变化范围的祖先端的个体比其他个体更容易患此病。更广泛地说，该研究表明，进化思维有可能为人类骨骼病理学提供新的思路。结论本研究的结果增加了假说H.sapiens的椎间盘突出与椎体形状有关的假说。具体而言，他们建议椎骨朝向智人内形状变化范围的祖先端的个体比其他个体更容易患此病。更广泛地说，该研究表明，进化思维有可能为人类骨骼病理学提供新的思路。智人比其他人更容易患病。更广泛地说，该研究表明，进化思维有可能为人类骨骼病理学提供新的思路。智人比其他人更容易患病。更广泛地说，该研究表明，进化思维有可能为人类骨骼病理学提供新的思路。