Doctoral Dissertation Improvement: Human Growth Evolving: Integrating Skeletal, Dental, and Cranial Proxies of Growth to Understand Ontogeny in Pleistocene Genus Homo

与现存最接近的近亲黑猩猩相比，现代人的特点是生长和发育(即个体发育)模式非常缓慢。在硬组织中，这一趋势在牙齿萌出较晚和骨骼成熟较晚时明显。这种延迟成熟对于大型大脑的发育以及掌握两足动物的运动和语言是必要的，但目前还不确定这种模式是在人类血统进化过程中何时出现的。现代人类和化石个体发育学的大多数研究都集中在牙齿或骨骼的发育上，使用其他发育系统作为年龄代用品。然而，为了正确理解现代人类个体发育模式的起源及其对人类进化的影响，不仅要了解牙齿和骨骼生长之间的关系，而且要了解发育事件的时间。本研究将通过结合不同地理区域现代人类骨骼样本的牙齿和骨骼生长发育数据来解决这一问题。它将包括牙齿形成和萌出的数据，几个颅骨成熟度指标，骨骺融合，以及长骨的长度和直径，并尽可能将它们与时间年龄联系起来。几个属于直立人、尼安德特人和早期智人的更新世化石，其死亡年龄将根据牙齿的微观结构估计，将与类似年龄的现代人进行比较，看看他们是否有共同的牙齿和/或骨骼生长和发育的共同模式和时间。这项研究的更广泛的意义包括首次尝试将化石中的牙齿和骨骼的生长和发育与大量和多样化的现代人样本进行比较，并将其与年代年龄联系起来。此外，大的现代人类样本将有助于重新评估和完善骨学标准。本研究将为一名女研究生的博士论文和培养工作做出贡献。最后，该项目将促进美国与非洲、亚洲和欧洲机构之间的国际合作。

Modern humans are characterized by a very slow pattern of growth and development (i.e. ontogeny) compared to the closest living relatives, the chimpanzees. In hard tissues this trend is evident in late eruption of teeth and late attainment of skeletal maturity. This delayed maturation is necessary for the development of large brains, and mastering bipedal locomotion and language, but it is still uncertain when this pattern arose during the evolution of the human lineage. Most studies of modern human and fossil ontogeny have focused on either dental or skeletal development, using the other developmental system as an age proxy. However, for a proper understanding of the origins of the modern human ontogenetic pattern, and its implications for human evolution, it is critical to understand not only the relationship between dental and skeletal growth, but also the timing of developmental events.This study will address this issue by combining data on dental and skeletal growth and development in modern human skeletal samples from different geographic regions. It will include data on dental formation and eruption, several cranial maturity indicators, epiphyseal fusion, and long bone lengths and diameters, and relate them to chronological age wherever possible. Several Pleistocene fossils belonging to H. erectus, Neanderthals, and early H. sapiens, whose age-at-death will be estimated from dental microstructure, will be compared to modern humans of similar age to see whether they share a common pattern and timing of dental and/or skeletal growth and development.The broader implications of this study include the first attempt to compare dental and skeletal growth and development in fossils to a large and diverse modern human sample, and to relate it to chronological age. Furthermore, the large modern human sample will be useful for re-evaluation and refinement of osteological standards. This research will contribute to the doctoral dissertation and training of a female graduate student. Finally, this project will foster international collaboration between the United States and institutions in Africa, Asia, and Europe.