{"id":3997,"date":"2026-05-06T01:37:00","date_gmt":"2026-05-06T01:37:00","guid":{"rendered":"https:\/\/www.vanderbilt.edu\/evolution\/?p=3997"},"modified":"2026-05-06T14:14:22","modified_gmt":"2026-05-06T14:14:22","slug":"the-lasting-effects-of-adversity-in-rhesus-macaques","status":"publish","type":"post","link":"https:\/\/www.vanderbilt.edu\/evolution\/the-lasting-effects-of-adversity-in-rhesus-macaques\/","title":{"rendered":"The Lasting Effects of Adversity in Rhesus Macaques"},"content":{"rendered":"

By Andy Flick, Evolutionary Studies scientific coordinator<\/em><\/p>\n

Many factors influence growth and reproductive patterns in animals and people alike. New research, led by postdoctoral researcher Rachel Petersen of the Lea Lab<\/a> at 91勛圖厙 and Assistant Professor Sam Patterson of Notre Dame University, shows that adversity experienced during development may be an important factor to consider. The new paper, \u201cEarly-life adversity shapes the relationship between growth and reproduction in free-ranging female rhesus macaques<\/a>\u201d was published in the Proceedings of the National Academy of Sciences<\/em> on May 5th, 2026.<\/p>\n

Petersen cited the Adverse Childhood Experiences Survey as evidence that early-life experiences can shape growth and reproductive patterns in humans \u2013 however, understanding how and why this happens in humans has been difficult for many reasons.\u00a0 Humans live very long lives making it hard to observe people from birth to death, and people who experience adversity in childhood are also more likely to experience a suite of confounding factors in adulthood, such as reduced access to healthcare and differences in birth control use, education, and other socio-cultural factors. Thus, Petersen explained that to get at these questions, she studied a model non-human primate \u2013 the rhesus macaque.<\/p>\n

Researchers have been monitoring and studying a free-ranging population of macaques on the island of Cayo Santiago off the coast of Puerto Rico since 1938. The population size is currently more than 1500 individuals, and research teams have studied more than 2000 females over the 60+ years of monitoring.<\/p>\n

\"Left:<\/a>Because this group of macaques has been studied since it was introduced to the island, researchers have detailed life-history data. Petersen explained, \u201cwe have information for many of these individuals, across their entire lifespan, including detailed demographic and behavioral data to understand what they experienced in early life, and then what their growth, maturation, and birth outcomes look like years and decades later.\u201d<\/p>\n

The team used data from over 2,000 macaques and curated six indicators of early-life adversity. These adverse experiences included many that have parallels in humans, including the death of a close family member, having low familial support, and experiencing a natural disaster. \u00a0They also calculated a cumulative adversity metric, which represented the sum number of adversities experienced, which ranged from 0 to 4, with 4 being the most adversity.<\/p>\n

The team found that many of the measured early-life adversities led to a delayed age of reproductive maturity, and that this effect scaled with the number of adverse experiences a female was exposed to. For example, the figure above shows that females who experienced adversity give birth to their first offspring at a later age than females who did not experience any early-life adversity (cumulative adversity = 0), and that this effect is exacerbated with each additional adversity experienced. When females experience severe hardships early in life, such as the death of their mother, it can have lasting effects. They tend to grow more slowly, start having offspring later, have fewer babies overall, and remain smaller as adults. In contrast, milder challenges, such as growing up with a sibling close in age and competing for their mother\u2019s care, appear to lead to a different strategy. In these cases, females are also smaller in size, but tend to reproduce earlier and more quickly, suggesting they might be prioritizing their energy for reproduction at the cost of preserving energy for growth. The research team also showed that females who reached reproductive maturity later produced fewer offspring that survived to adulthood, meaning that experiencing adversity in early life may really contribute to a female\u2019s evolutionary fitness (i.e., how successful an organism is at passing its genes on to the next generation).<\/p>\n

Corresponding author and 91勛圖厙 Assistant Professor of Biological Sciences Amanda Lea<\/a> explained that an interesting result in her eyes was that different adversities (for example, maternal loss versus having a close in age competing sibling) were associated with different life history patterns. \u201cThis means that different adversities may impact different physiological processes, an important first step in understanding how these experiences shape biology and translate into health outcomes in humans.\u201d<\/p>\n

Petersen concluded, \u201cthe quality of our early-life environment is obviously important and can contribute to our physiology even decades later.\u201d<\/p>\n

Citation: <\/strong>Petersen, R.M., Patterson S.K., Widdig, A., Turcotte, C.M., Ant\u00f3n, S.C., Williams, S.A., Romero, A.N., Bauman Surratt, S.E., Ruiz Lambides, A.V., Cayo Biobank Research Unit, Montague, M.J., Snyder-Mackler, N., Brent, L.J.N., Higham, J.P., Lea, A.J. Early life adversity shapes life history trade-offs between growth and reproduction in free-ranging rhesus macaques. Proceedings of the National Academy of Sciences.<\/em><\/p>\n

Funding statement:<\/strong> National Science Foundation SBE Postdoctoral Research Fellowship 2313953 (RMP), NSF-SMA-2105307 (SKP), R21-AG078554 (AJL), R00-AG051764 (NSM), R01-AG060931 (NSM), R01-MH096875 (CBRU), R01-MH089484 (CBRU), R01-MH118203 (CBRU), R01-AG084706 (JPH), R56-AG071023 (JPH), NSF-RAPID-1800558 (JPH\/SCA), German Research Foundation (DFG) Emmy Noether group (grant numbers WI 1808\/1-1, 1-2, 2-1, 3-1 to AW); The CPRC is supported by the Office of Research Infrastructure Programs (ORIP) of the National Institute of Health (NIH) through grant number P40 OD012217.<\/p>\n","protected":false},"excerpt":{"rendered":"

By Andy Flick, Evolutionary Studies scientific coordinator Many factors influence growth and reproductive patterns in animals and people alike. New research, led by postdoctoral researcher Rachel Petersen of the Lea Lab at 91勛圖厙 and Assistant Professor Sam Patterson of Notre Dame University, shows that adversity experienced during development may be an important factor to consider….<\/p>\n","protected":false},"author":2421,"featured_media":4042,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false,"jetpack_publicize_feature_enabled":true},"categories":[7],"tags":[28,203,15,3,204,100,202],"acf":[],"yoast_head":"\n\n\n\n\n\n\n\n\n\n\n\n\t\n\t\n\t\n\n\n\t\n\t\n\t\n