Doctoral Dissertation Research: Optimal time scales for integrating paleoecological and fossil data in human evolutionary studies

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).

Humans have a unique suite of biological adaptations, many of which can be observed at various points in the primate and human evolutionary fossil record. To investigate how and why these adaptations occurred, it is critical that scientists consider not only the fossils themselves but their ecological and environmental contexts. This doctoral dissertation project addresses important questions about the optimal time scale(s) for investigating links between early humans and their environments.

The investigators use data from high-resolution geological sediments to reconstruct and analyze environmental change at various scales of observation and consider how different patterns emerge depending on scale. The project also includes opportunities for student training and mentoring, public science outreach activities, and strengthening of international research collaborations.

Interpretations of large- and small-scale paleoecological trends are developed to assess how scale may influence interpretations of mammalian dietary ecology, as well as early human environments within a relatively continuous geologic sequence where fossil apes and humans have been recovered. The investigators develop long-term, coarsely resolved dietary data for 8 herbivore lineages for periods from 13-8.5 Ma and 5.3-1.6 Ma.

They develop temporally refined, short-term dietary data for herbivores from 4-2 Ma. Each fossil sample is correlated to a specific geologic horizon— and subsequently a specific date—for which detailed paleoclimatic and paleobotanical data have been published. The project enables the diets of individual animals to be reconstructed to the level of vegetation type and then be compared to outstanding paleoclimatic datasets in order to better understand prevailing modes of paleoecological change in the region.

These data can advance the integration of paleoecological patterns at various temporal scales to help clarify the types of environmentally-selective forces experienced by the hominin and hominoid lineages.

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.