NSF PRFB FY 2023: Connecting physiological and cellular aging to individual quality in a long-lived free-living mammal.

Evans, Taylor C, Washington DC

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. The ability of an organism to reproduce in specific environments (fitness), is not evenly distributed within populations. There are differing predictions that investing in current reproduction comes at a cost to survival and future reproduction. One hypothesis called the individual quality framework suggests that some individuals show higher ‘quality’, both reproducing more effectively and surviving longer. These ‘high quality’ individuals may be more able to weather adverse conditions and maintain reproduction while comparatively lower quality individuals are more impacted by negative environments such as food scarcity or land disturbance. This research will take advantage of a well-studied population of grey seals (Halichoerus grypus) that breed on Sable Island to evaluate the individual quality hypotheses. The fellow will collaborate with government scientists and community members in Canada at Sable Island National Park to increase public interest in the Sable Island seals and promote the value of long-term studies. Telomeres, repeating DNA segments which degrade with cell division and protect chromosomes from oxidative stress, are a gauge of somatic wear and may provide a metric for overall quality, thus linking cellular aging to expressed reproductive fitness. The fellow will resample DNA from marked seals that had early-life genetic samples collected at weaning. Telomere length will be estimated for new and archived samples using qPCR, and these lengths will provide telomere erosion rate. Telomere dynamics will be related to lifetime reproductive effort observed for each seal to evaluate whether longer, slower eroding telomeres correlate with higher reproductive success and survival. The project will also investigate whether ‘quality’ in terms of telomere dynamics is heritable, and whether maternal foraging strategy provides a pathway for the transmission of quality to offspring. The fellow will gain experience with telomere assays as well as Bayesian mark-recapture and state-space population modeling. For each field season during this work, the fellow will conduct targeted recruitment of undergraduate students from underrepresented groups to be research assistants, leveraging this project to expand access to fieldwork and broaden participation in behavioral ecology. 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.