The detailed anatomical features that characterize fossil hominin molars figure prominently in the reconstruction of their taxonomy, phylogeny, and paleobiology. Despite the prominence of molar form in human origins research, the underlying developmental mechanisms generating the diversity of tooth crown features remain poorly understood. A model of tooth morphogenesis-the patterning cascade model (PCM)-provides a developmental framework to explore how and why the varying molar morphologies arose throughout human evolution. We generated virtual maps of the inner enamel epithelium-an indelibly preserved record of enamel knot arrangement-in 17 living and fossil hominoid species to investigate whether the PCM explains the expression of all major accessory cusps. We found that most of the variation and evolutionary changes in hominoid molar morphology followed the general developmental rule shared by all mammals, outlined by the PCM. Our results have implications for the accurate interpretation of molar crown configuration in hominoid systematics.

中文翻译：

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牙齿发育的Evo-devo模型和类人牙齿磨牙多样性的起源。

化石人磨牙特征的详细解剖特征在其分类学，系统发育和古生物学的重建中占有重要地位。尽管在人类起源研究中臼齿形式很突出，但产生齿冠特征多样性的潜在发展机制仍然知之甚少。牙齿形态发生模型-模式级联模型（PCM）提供了一个发展框架，以探讨在整个人类进化过程中如何以及为什么产生不同的磨牙形态。我们绘制了搪瓷内膜上皮的虚拟图谱-搪瓷结排列的不可磨灭的记录-在17种活体和化石类人猿物种中进行研究，以调查PCM是否解释了所有主要副瓣的表达。我们发现，类人猿臼齿形态的大多数变化和进化变化遵循所有哺乳动物共有的一般发育规律，如PCM概述。我们的结果对类人系统中磨牙冠构型的准确解释具有重要意义。