Effects of early life adversity on the pace of aging in rhesus macaques

This award was provided as part of NSF's Social, Behavioral and Economic Sciences Postdoctoral Research Fellowships (SPRF) program. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research.

NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields.

Under the sponsorship of Dr. James Higham at New York University, Dr. Noah Snyder-Mackler at Arizona State University, and Dr.

Lauren Brent at the University of Exeter, this postdoctoral fellowship award supports an early career scientist investigating whether early life adversity reduces life expectancy and accelerates aging in free ranging rhesus macaques (Macaca mulatta). Exposure to social and ecological hardships during early development can exert negative effects on aging health and survival in a wide range of species including humans.

However, the biological mechanisms underlying these consequences of early adversity are not well understood. Given the rapidly growing aging-population, there is an urgent need to determine the type of factors and their timing that affect variation in the pace of aging. The present study has the unique benefit of incorporating historical data with expansive longitudinal biological sampling to produce the most comprehensive model of early life adversity and aging to date.

Further, by studying a close primate relative in a naturalistic environment, this research takes a comparative evolutionary approach and adds to our understanding of the context in which these early life effects evolved and how they vary across species and environments. This research fills important gaps in our understanding of the mechanisms and evolution of human aging health and can thus improve our understanding of how to address disparities in human health stemming from early life adversity.

Adverse experiences in early life can have profound lasting consequences, such as increased susceptibility to diseases, but exactly how early life adversity influences the physical, physiological, and cellular declines that begin prior to disease and death is less understood. The present research investigates how early life adversity predicts lifespan and the pace of aging in a population of free ranging rhesus macaques.

No other population of nonhuman primates offers the opportunity to study early life adversity in relation to multiple domains of aging. The proposed study capitalizes on long-term demographic data alongside detailed behavioral, molecular, physiological, and physical data to characterize each animal’s adverse experiences early in life (e.g., parental loss, low social status, social isolation, and presence of a competing sibling) and evaluate how this predicts survival and longitudinal aging across domains.

Repeated biological samples are collected from individuals, which include endocrine and immune biomarkers (e.g., HPA-axis function, immune activation, inflammation), molecular biomarkers (e.g., DNA methylation, telomere attrition, mitochondrial function), and physical biomarkers (e.g., body condition, facial aging, joint mobility, gait speed). By conducting a study with both a lifespan perspective and an expansive set of biomarkers measured longitudinally across adulthood, these findings will establish a comprehensive model for the evolution of early life effects, as a foundation for future research in comparative biological anthropology and evolutionary medicine.

The multi-output analyses will identify whether early life adversity affects some domains of aging more than others and if some domains of aging precede others. Together the results of the proposed study will shed light on the evolution of responses to early life adversity, and contribute to our understanding of how and why individuals age differently.

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.