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

New York University, New York NY

Investigators

Abstract

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.