Biomechanical Evolution of Enamel and the Diversification of Vertebrates

许多物种的进化是由摄食能力的变化促进的。广泛的测试表明，牙齿尺寸，形状和咬合力的变化是喂养能力的关键决定因素。然而，牙组织力学性能的变化，也可能在这一过程中发挥不可或缺的作用，很少被理解。由于牙组织非常细小，因此缺乏有关材料级机械能力的数据，因此无法进行大多数测试。在目前的研究中，这一问题将通过一种名为纳米压痕（小型化机械测试）的新工程技术来克服，从而可以测量小材料的强度、硬度和抗刮擦性。该方法将应用于牙釉质（食物与牙列之间的主要接触组织），这些牙釉质来自多种具有广泛进食能力的物种。本研究产生的数据将有助于将目前牙齿形态学和生物力学的数据联系在一起。此外，它将使这一领域更接近于全面理解动物喂养的形式、功能和生态学——过去和现在——包括我们自己的牙齿是如何以及为什么这样运作的。

The evolution of many species was facilitated by changes in feeding capacity. Extensive testing has shown modifications in tooth size, shape, and biting forces are critical determinants of feeding capacity. However, changes in the mechanical performance of dental tissues, which may also play an integral role in this process, are little understood. Data regarding material level mechanical capacity is lacking since dental tissues are minute and preclude most testing protocols. In the present research this problem will be overcome using a new engineering technique called nano-indentation (miniaturized mechanical testing) whereby the measurement of strength, hardness, and scratch-resistance of small materials is feasible. The method will be applied to enamel (the primary contact tissue between food items and the dentition) from a diversity of species with a broad range of feeding abilities. The data generated from this study will serve to tie together the current data on dental morphology and biomechanics. Furthermore it will move the field considerably closer to a comprehensive understanding of the form, function, and ecology of animal feeding--past and present--including how and why our own dentitions function as they do.