Doctoral Dissertation Research: Histological and elemental markers of reproductive physiology in mineralized hard tissues

人类的生长、发育、繁殖和衰老的模式与我们现存最接近的灵长类亲戚相比是不寻常的，在整个灵长类动物中也是独一无二的。人类的寿命非常长，出生间隔很近，幼年依赖期延长，生育后的雌性支持抚养后代。这些独特的生活史特征与现代人观察到的社会(共同照顾婴儿)和认知(例如创新)特征有关。这项博士论文研究项目将使用最先进的显微镜和化学方法，通过分析我们已经灭绝的亲戚化石遗骸中的生物历史，来推进现代人类生命历史如何演变的当前知识。这项研究结果可能会为与年龄、生殖和/或代谢状况相关的硬组织疾病的临床研究提供信息。该项目将涉及纽约大学少数民族本科生在实验室工作和数据收集过程中的培训。这项研究的成果将通过博物馆外展活动和国际合作向更广泛的受众展示。该项目将使用尖端技术来研究与生殖生理有关的骨骼和牙齿的变化。骨骼和牙齿以生长层改变的形式记录影响生物体的生理影响事件。研究人员将制作组织学薄片，使用光学和电子显微镜检查这些生长层。此外，将对生长层进行完整的元素分析，并将构建各种类型事件(怀孕、更年期、性成熟以及疾病和其他生理应激源)的“元素指纹”库。最后，由于出于保存的原因，我们已经灭绝的亲戚的化石遗骸不能进行物理切片，该项目将利用极高能量和高分辨率的显微断层扫描(相衬同步辐射计算机显微断层扫描)，以非破坏性的方式获得牙齿的内部结构。该项目开发的方法将为未来应用于人类化石记录奠定基础。这一奖项反映了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。

The human pattern of growth, development, reproduction and aging is unusual compared to that of our closest living primate relatives and distinctive among primates as a whole. Humans have exceptionally long lifespans, closely spaced births, an extended period of juvenile dependence and support in raising offspring by post-reproductive females. These unique life history traits have been linked to social (shared infant care) and cognitive (e.g. innovativeness) traits observed in modern humans. This doctoral dissertation research project will use state-of-the-art microscopy and chemical methods to advance current knowledge about how modern human life history evolved, by analyzing biological ‘histories’ in the fossilized remains of our extinct relatives. The study findings may inform clinical research on hard tissue diseases associated with age, reproduction and/or metabolic conditions. This project will involve the training of minority undergraduate students at NYU in the processes of lab work and data collection. The outcomes of this research will be presented to a wider audience through museum outreach activities and international collaborations.This project will use cutting-edge technologies to investigate changes in bone and teeth related to reproductive physiology. Bones and teeth record physiologically impactful events affecting the organism in the form of altered growth-layers. The investigator will generate histological thin sections to examine these growth layers using both optical and electron microscopy. In addition, complete elemental analysis of the growth layers will be carried out and a library of “elemental fingerprints” of the various types of events (pregnancy, menopause, sexual maturity, as well as illnesses and other physiological stressors) will be constructed. Finally, since the fossil remains of our extinct relatives cannot be physically sectioned for preservation reasons, the project will utilize extremely high-energy and high-resolution microtomography (phase-contrast synchrotron radiation computed micro-tomography) to gain access to the internal structure of teeth in a non-destructive way. The methods developed in this project will lay the groundwork for future application to the hominin fossil record.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.