1Anthropology Department, Rutgers University, New Brunswick, 2Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, 3Anthropology Department, Rutgers University Center for Human Evolutionary Studies, 4Anthropology Department, University of California, Santa Cruz, 5Department of Collective Behavior, Max Planck Institute of Animal Behavior, Konstanz
April 16, 2020 , Platinum Ballroom
The isotopes of trace metals, such as iron (Fe) and copper (Cu) have been shown to be less in human adult males relative to females, and this sex effect has been linked to female menstruation. However, this variation has never been measured in non-human primates. We hypothesized that because rhesus macaques have a similar menstrual cycle to humans, the sex variation in Fe and Cu should be similar to adult humans. To test if there was a similar sex effect in rhesus macaques, we investigated the isotopic fractionation of δ56Fe and δ65Cu of 20 pre- and peri-pubescent rhesus macaques (Macaca mulatta) from the Caribbean Primate Research Center, Puerto Rico. We sampled bulk occipital bone and incisors, from which Fe and Cu were separated and measured by MC-ICP-MS. Our results show that there is a significant relationship between δ65Cu fractionation and sex in rhesus macaque occipital bone (p = 0.0014), with δ65Cu values higher by 1.4 ‰ in males compared to females. This effect was not present in incisors, which reflect earlier, pre-pubescent life stages. However, we found an interaction between age and sex that affects δ65Cu fractionation in rhesus macaque occipital bone, suggesting that age could potentially influence δ65Cu fractionation depending on the sex of the individual. We found no significant relationship between δ56Fe values and sex in rhesus macaque occipital bone or incisors. Our results show that Cu metabolism has the potential to be a useful supplementary tool in future primatological, archaeological and paleoanthropological studies.
Rutgers Center for Human Evolutionary Studies (CHES) Barry C. Lembersky Undergraduate Research Award, Aresty Research Center Undergraduate Research Fellowship, and Bigel Endowment in Anthropology