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

现代人类的特征是与现存的近亲黑猩猩相比，生长和发育（即个体发育）非常缓慢。在硬组织中，这种趋势在牙齿萌出较晚和骨骼成熟较晚时表现得很明显。这种延迟的成熟对于大脑的发育，以及掌握两足动物的运动和语言是必要的，但在人类谱系的进化过程中，这种模式何时出现仍然不确定。大多数现代人类和化石个体发育的研究都集中在牙齿或骨骼的发育，使用其他发育系统作为年龄代理。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，本研究将通过结合来自不同地理区域的现代人类骨骼样本中牙齿和骨骼生长发育的数据来解决这个问题。它将包括关于牙齿形成和萌出、几个颅骨成熟指标、骨骺融合以及长骨长度和直径的数据，并尽可能将其与实足年龄相关联。更新世的几个化石属于H。直立人、尼安德特人和早期人类将通过牙齿显微结构来估计智人的死亡年龄，并将其与相似年龄的现代人进行比较，以了解他们是否具有共同的牙齿和/或骨骼生长和发育模式和时间，这项研究的更广泛意义包括首次尝试将化石中的牙齿和骨骼生长和发育与大量不同的现代人样本进行比较，并将其与实足年龄相关联。此外，大量的现代人类样本将有助于重新评估和完善骨骼学标准。这项研究将有助于博士论文和培养一名女研究生。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.