Doctoral Dissertation Research: Dental function and tooth wear in the evolution of primate molar form

东半球猴子是现存的灵长类动物中地理分布最广、生态最多样化的一类，它们的肠道适应能力和磨牙的独特形状相结合，使它们有可能获得广泛的饮食。东半球的猴子获得了“双齿猴”的磨牙，它们的尖牙结合成两对楔形，不久就从最后一个与猿类共同的祖先那里分离出来。这个博士论文项目将调查这种磨牙形态转变的功能意义，借鉴并促进一个框架，该框架考虑牙齿磨损如何在有机体的一生中改变牙齿的形状和功能。该项目还将提供公共宣传和本科生研究参与的机会，包括传统上在STEM职业生涯中代表性较低的学生。该项目产生的大量3D扫描将通过MorPhoSource公开提供，在那里它们可以进一步用于科学和教育目的。像所有食草性哺乳动物一样，灵长类面临着在牙齿磨损的情况下保持恒牙功能的选择压力。该项目将使用3D牙齿地形图方法来测量现存和化石卡他类动物(即东半球猴子、猿类和人类)样本中不同磨损阶段磨牙的剪切和粉碎/研磨潜力。首先，研究人员将建立现存的卡他磨牙如何因宏观磨损而改变的基线，并使用系统发育比较方法来测试饮食或牙齿形态对维持剪切功能的影响是否更大。其次，这些方法将被应用于测量渐新世和中新世卡他犀类的磨牙的剪切和粉碎/研磨潜力。虽然现存的东半球猴子的磨牙上有两个完全发育的Loph，但这个分支的早期成员在一些磨牙上表现出部分Loph的发育。研究人员将测试这些早期的双齿动物是否使干细胞类棘齿动物相对于它们的非脊椎动物类卡他类动物具有更强的某些牙齿功能的持久性。最终，这个项目将有助于我们理解有助于旧大陆猴子饮食灵活性和进化成功的关键适应背后的功能起源。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Old World monkeys are the most geographically widespread and ecologically diverse group of living primates, with a wide range of diets made possible by the combination of their gut adaptations and the unique shape of their molar teeth. Old World monkeys acquired "bilophodont" molars, with cusps united into two pairs of wedges, soon after diverging from a last common ancestor with apes. This doctoral dissertation project will investigate the functional significance of this shift in molar form, drawing upon, and contributing to, a framework that considers how dental wear alters the shape and function of teeth throughout an organism's life. This project will also provide opportunities for public outreach and undergraduate research engagement, including students traditionally underrepresented in STEM careers. The large number of 3D scans generated by this project will be made publicly available through MorphoSource, where they can have further use for scientific and educational purposes. Primates, like all herbivorous mammals, face selective pressures to maintain function of their permanent teeth in the face of tooth wear. This project will use 3D dental topographic methods to measure the shearing and crushing/grinding potential of molars at varying wear stages in a sample of extant and fossil catarrhines (i.e., Old World monkeys, apes, and humans). First, the investigators will establish a baseline of how extant catarrhine molars are altered by macroscopic wear and use phylogenetic comparative methods to test whether diet or tooth morphology has a greater influence on maintenance of shearing function. Second, these methods will be applied to measure the shearing and crushing/grinding potential from molars of Oligocene and Miocene catarrhines. While extant Old World monkeys have two fully developed lophs on their molars, early members of this clade exhibit partial loph development in some molars. The investigators will test whether these early stages of bilophodonty gave stem cercopithecoids greater persistence of certain tooth functions relative to their non-cercopithecoid catarrhine relatives. Ultimately, this project will contribute to our understanding of the functional origins underlying a key adaptation that contributes to the dietary flexibility and evolutionary success of Old World monkeys.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.