Testing Adaptive Hypotheses of Plio-Pleistocene Hominin Craniofacial Evolution

这个项目解决了灭绝的人类的主要群体彼此之间的进化分歧，特别关注与饮食和认知相关的形态变化。这些结果将推进有关进化过程的知识，揭示饮食驱动的自然选择如何与现有的形态整合模式相互作用，以产生进化变化。该项目将支持一名女性调查员，并扩大科学基础设施。它还将为来自代表性不足群体的博士后研究人员和本科生提供3D扫描，喂养生物力学和进化建模方面的培训机会，从而扩大科学参与。研究人员将使用NSF支持的CREATE方法，使用该项目的结果制作本科教学模块。该研究还将收集和存档许多3D表面模型和生物力学测量结果，供其他研究人员和学生使用。拟议的研究将测试有关自然选择在人类进化中的作用的假设，包括：1）对加工坚硬或坚韧食物的选择推动了南方古猿头骨的进化，南方古猿是一群早期人类祖先，2）复杂认知的选择导致了我们人类属早期成员的大脑（以及脑颅）。研究人员将利用现有的定量遗传学测试，可以区分自然选择和中性进化过程，使用形态学数据，这些数据提供有关咀嚼生物力学和大脑大小的信息。研究人员将测量从三个主要的上新世-更新世人类群体的化石表面扫描生成的3D模型：傍人，南方古猿和早期人属。此外，从现存物种的测量将被用来模拟人口模式的性状变异和协变作为代理的灭绝物种。性状变异和协变的程度是影响种群响应自然选择能力的关键参数，也是影响种群因遗传漂变等随机过程而发生变化的方式的关键参数。该研究的创新方面包括使用生物力学信息变量来测试有关选择和评估测试对选择化石活代理的敏感程度的假设。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This project addresses the evolutionary divergence of major groups of extinct hominins from one another, with a particular focus on morphological changes associated with diet and cognition. The results will advance knowledge about evolutionary processes, shedding light on how diet-driven natural selection can interact with existing patterns of morphological integration to produce evolutionary change. The project will support a female Investigator and expand scientific infrastructure. It will also generate opportunities for training in 3D scanning, feeding biomechanics and evolutionary modeling for a postdoctoral researcher and an undergraduate student from an underrepresented group, thus broadening participation in science. The investigators will use the NSF-supported CREATE approach to produce an undergraduate teaching module using the results of this project. The research will also result in the collection and archiving of many 3D surface models and biomechanical measurements to be used by other researchers and students.The proposed research will test hypotheses about the role of natural selection in hominin evolution, including that: 1) selection for processing hard or tough foods drove skull evolution in australopiths, a group of early human ancestors, and 2) selection for complex cognition led to large brains (and thus neurocrania) in early members of our own genus, Homo. The researchers will take advantage of existing quantitative genetics tests that can distinguish between natural selection and neutral evolutionary processes using morphological data that are informative about chewing biomechanics and brain size. The researchers will measure 3D models generated from surface scans of fossils from three major groups of Plio-Pleistocene hominins: Paranthropus, Australopithecus and early Homo. In addition, measurements from extant species will be used to model population patterns of trait variation and covariation as proxies for the extinct species. The extent of trait variation and covariation are key parameters influencing the ability of a population to respond to natural selection, as well as the manner in which populations change due to random processes like genetic drift. Innovative aspects of the research include the use of biomechanically informative variables to test hypotheses about selection and assessment of how sensitive tests are to choice of living proxy for the fossils.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.