Melissa Emery Thompson | University of New Mexico (original) (raw)

Papers by Melissa Emery Thompson

Endocrinology of Social Relationships

As a taxonomic group, the hominoids share many anatomical and behavioral features. Despite this, ... more As a taxonomic group, the hominoids share many anatomical and behavioral features. Despite this, the 18 species and 23 subspecies in this group display a remarkably diverse range of social structures and mating systems (Table 9.1). Accordingly, there is variation in the pressures and constraints on male-female sexual relationships across these species. In this chapter, I focus on the diversity of social and sexual relationships between males and females in ape societies, with emphasis on how hormonal information has helped make ...

Encyclopedia of Evolutionary Psychological Science

PLOS ONE

Oxidative stress (OS) plays a marked role in aging and results from a variety of stressors, makin... more Oxidative stress (OS) plays a marked role in aging and results from a variety of stressors, making it a powerful measure of health and a way to examine costs associated with life history investments within and across species. However, few urinary OS markers have been examined under field conditions, particularly in primates, and their utility to non-invasively monitor the costs of acute stressors versus the long-term damage associated with aging is poorly understood. In this study, we examined variation in 5 urinary markers of oxidative damage and protection under 5 validation paradigms for 37 wild, chimpanzees living in the Kibale National Park, Uganda. We used 924 urine samples to examine responses to acute immune challenge (respiratory illness or severe wounding), as well as mixed-longitudinal and intra-individual variation with age. DNA damage (8-OHdG) correlated positively with all other markers of damage (F-isoprostanes, MDA-TBARS, and neopterin) but did not correlate with protection (total antioxidant capacity). Within individuals, all markers of damage responded to at least one if not both types of acute infection. While OS is expected to increase with age, this was not generally true in chimpanzees. However, significant changes in oxidative damage were detected within past-prime individuals and those close to death. Our results indicate that OS can be measured using field-collected urine and integrates short-and long-term aspects of health. They further suggest that more data are needed from long-lived, wild animals to illuminate if common age-related increases in inflammation and OS damage are typical or recently aberrant in humans.

Hormones and Behavior

A key goal in behavioral ecology is to investigate the factors influencing the access to food res... more A key goal in behavioral ecology is to investigate the factors influencing the access to food resources and energetic condition of females, which are strong predictors of their reproductive success. We aimed to investigate how ecological factors, social factors, and reproductive state are associated with energetic condition in a wild neotropical primate using non-invasive measures. We first assessed and compared urinary C-peptide levels (uCP), the presence of urinary ketones (uKet), and behaviorally assessed energy balance (bEB) in female white-faced capuchin monkeys (Cebus imitator) living in Santa Rosa, Costa Rica. Then, we assessed how these measures were associated with feeding competition, dominance rank, and reproductive status. As predicted, uCP and bEB were positively associated with each other, and bEB was negatively associated with uKet. However, we did not find a relationship between uCP and uKet. Females showed lower uCP and bEB values during periods of intense feeding competition, but this relationship was not dependent on dominance rank. Furthermore, rank was not directly associated with uCP and bEB. Urinary ketones, on the other hand, were only produced in the most adverse conditions: by low-ranking, lactating females during periods of intense food competition. Behavioral strategies are assumed to maximize reproductive success and not energetic condition per se, which might explain why rank was not generally associated with energetic condition in our study population. This highlights the importance of considering potential differences between reproductive success and proxies of reproductive success, such as energetic condition or food intake, when investigating predictions of socioecological models.

Hormones and Behavior

Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone i... more Decades of research in behavioral endocrinology has implicated the gonadal hormone testosterone in the regulation of mating effort, often expressed in primates in the form of aggressive and/or status-striving behavior. Based on the idea that neuroendocrine axes influence each other, recent work among humans has proposed that links between testosterone and indices of status-striving are rendered conditional by the effects of glucocorticoids. The Dual Hormone hypothesis is one particular instance of this argument, predicting that cortisol blocks the effects of testosterone on dominance, aggression, and risk-taking in humans. Support for the Dual Hormone hypothesis is wide-ranging, but considerations of theoretical ambiguity, null findings, and low statistical power pose problems for interpreting the published literature. Here, we contribute to the development of the Dual Hormone hypothesis by (1) critically reviewing the extant literature-including p-curve analyses of published findings; and, (2) "opening the file drawer" and examining relationships between testosterone, cortisol, and status-striving personality features in seven previously published studies from our laboratories (total N = 718; median N per feature = 318) that examined unrelated predictions. Results from p-curve suggest that published studies have only 16% power to detect effects, while our own data show no robust interactions between testosterone and cortisol in predicting status-striving personality features. We discuss the implications of these results for the Dual Hormone hypothesis, limitations of our analyses, and the development of future research.

American Journal of Primatology

Emerging infectious diseases, Feb 1, 2018

We describe a lethal respiratory outbreak among wild chimpanzees in Uganda in 2013 for which mole... more We describe a lethal respiratory outbreak among wild chimpanzees in Uganda in 2013 for which molecular and epidemiologic analyses implicate human rhinovirus C as the cause. Postmortem samples from an infant chimpanzee yielded near-complete genome sequences throughout the respiratory tract; other pathogens were absent. Epidemiologic modeling estimated the basic reproductive number (R) for the epidemic as 1.83, consistent with the common cold in humans. Genotyping of 41 chimpanzees and examination of 24 published chimpanzee genomes from subspecies across Africa showed universal homozygosity for the cadherin-related family member 3 CDHR3-Yallele, which increases risk for rhinovirus C infection and asthma in human children. These results indicate that chimpanzees exhibit a species-wide genetic susceptibility to rhinovirus C and that this virus, heretofore considered a uniquely human pathogen, can cross primate species barriers and threatens wild apes. We advocate engineering interventio...

Hormones and behavior, Jan 13, 2017

The relationship between male mating opportunities, stress, and glucocorticoid concentrations is ... more The relationship between male mating opportunities, stress, and glucocorticoid concentrations is complicated by the fact that physiological stress and glucocorticoid concentrations can be influenced by dominance rank, group size, and the stability of the male dominance hierarchy, along with ecological factors. We studied the three highest-ranking males in nine different social groups within the same free-ranging population of rhesus macaques on Cayo Santiago, Puerto Rico, during the mating season, to examine variation in glucocorticoid concentrations in relation to number of females that conceived each month, alpha status, number of adult males in a group, and male rank hierarchy stability. We found that glucocorticoid concentrations were highest in the early mating season period when more females conceived in each group and declined linearly as the mating season progressed and the number of conceptive females decreased. Alpha males had significantly higher mean monthly glucocortico...

American Journal of Physical Anthropology

Primates have an extended period of juvenility before adulthood. Although dietary complexity play... more Primates have an extended period of juvenility before adulthood. Although dietary complexity plays a prominent role in hypotheses regarding the evolution of extended juvenility, the development of feeding behavior is still poorly understood. Indeed, few studies have investigated the timing and nature of feeding transitions in apes, including chimpanzees. We describe general patterns of feeding development in wild chimpanzees and evaluate predictions of the needing-to-learn hypothesis. We analyzed 4 years of behavioral data (2010-2013) from 26 immature chimpanzees and 31 adult chimpanzees of the Kanyawara community in Kibale National Park, Uganda. Specifically, we examined milestones of nutritional independence (first consumption of solid food and cessation of suckling) as well as developmental changes in feeding time, diet composition, diet breadth, and ingestion rates. Chimpanzees first fed on solid food at 5.1 months and, on average, suckled until 4.8 years. Daily feeding time of immature individuals reached adult levels between 4 and 6 years, while diet composition showed minor changes with age. By juvenility (5-10 years), individuals had a complete adult diet breadth. Ingestion rates for five ripe fruit species remained below adult levels until juvenility but continued to show absolute increases into adolescence. Chimpanzees acquired adult-like patterns on all feeding measures by infancy or juvenility. These data are inconsistent with the needing-to-learn hypothesis; moreover, where delays exist, alternatives hypotheses make similar predictions but implicate physical constraints rather than learning as causal factors. We outline predictions for how future studies might distinguish between hypotheses for the evolution of extended juvenility.

Personality and Individual Differences, 2016

An important dimension of individual differences, independent of general cognitive ability (GCA),... more An important dimension of individual differences, independent of general cognitive ability (GCA), is specialization for verbal or spatial ability. In this study we investigated neuroanatomic, network, and personality features associated with verbal vs. spatial ability. Healthy young adults (N = 244) were evaluated with (1) a cognitive battery yielding measures of verbal and spatial ability independent of GCA, (2) structural MRI scans providing measures of surface area, cortical thickness, and DTI scans allowing calculation of diverse network metrics, and (3) Big-5 personality measures. Sex differences were found for cognitive, personality, anatomic, and network measures. In men only, cortical surface was significantly, differentially related to the cognitive variables, predicting spatial but not verbal ability. Similarly, in men only, neuroticism and quirkiness (the overall deviation from the mean across scales) were significantly, differentially related to the two cognitive variables. Different graph metrics predicted spatial ability in men (overall connectivity) and women (clustering). Verbal-spatial specialization was related to sex, cortical surface area, network organization, personality, and vocational interests. Most of the identified correlates of this cognitive specialization were found only in men, and mostly for spatial ability. Taken together, these results identify a suite of neurobehavioral features whose covariance is partially sex-specific.

Hormones and Behavior, 2016

In naturally cycling women, Roney and Simmons (2013) examined hormonal correlates of their desire... more In naturally cycling women, Roney and Simmons (2013) examined hormonal correlates of their desire for sexual contact. Estradiol was positively associated, and progesterone negatively associated, with self-reported desire. The current study extended these findings by examining, within a sample of 33 naturally cycling women involved in romantic relationships, hormonal correlates of sexual attraction to or interests in specific targets: women's own primary partner or men other than women's primary partner. Women's sexual interests and hormone (estradiol, progesterone, and testosterone) levels were assessed at two different time points. Whereas estradiol levels were associated with relatively greater extra-pair sexual interests than in-pair sexual interests, progesterone levels were associated with relatively greater in-pair sexual interests. Both hormones specifically predicted in-pair sexual desire, estradiol negatively and progesterone positively. These findings have implications for understanding the function of women's extended sexuality - their sexual proceptivity and receptivity outside the fertile phase, especially during the luteal phase.

The question of whether female primates, in promiscuously breeding species, exhibit preferences f... more The question of whether female primates, in promiscuously breeding species, exhibit preferences for particular males, and subtly attempt to bias paternity, is famously intractable. Previous studies from three sites have shown that, in wild chimpanzees (Pan troglodytes), females mate more restrictively during the fertile period, and this has been taken as evidence for female choice. A common problem with these studies, however, was a failure to test whether females sexual solicitations and refusals, during periods when females are ...

Brain, Behavior, and Immunity, 2015

Dominance acquisition in rhesus macaques typically happens via queuing: males do not compete aggr... more Dominance acquisition in rhesus macaques typically happens via queuing: males do not compete aggressively to become alphas but wait for their turn upon immigrating into a new group, with their rank increasing with group tenure length. We report an unusual series of events, involving the take-over of a group’s alpha position by a new immigrant male (11Z) at the beginning of the 2013 mating season on Cayo Santiago, Puerto Rico, the unsuccessful attempts of resident male coalitions to dominate him, his extremely high mating success through the mating season, and and his drop to the bottom of the hierarchy after end of mating. The drop in ranking affected his sociality, space use, and access to food. 11Z’s high reproductive effort during the 2013 mating season and his inability to regain condition over the next months due to loss of alpha status resulted in him showing the highest relative body weight loss of all males in the group in the lead-up to the next mating season. We suggest th...