Understanding and predicting the effects climate change, habitat loss, and other human disturbances on natural populations is one of the grand challenges for today’s natural scientists.
My research is in the broad area of behavioral responses to changing environments, both ecological and social. We still do not fully understand the limits of behavioral flexibility or whether adaptive responses will be sufficient to keep pace with rapidly changing environmental conditions. These gaps in our understanding motivate the goals of my research: to shed light on the limits, consequences, and evolutionary roots of flexible responses to environments that change in time or space.
I study natural primate populations, including white-faced capuchins in Costa Rica’s Área de Conservación Guanacaste and savannah baboons in the Amboseli ecosystem of East Africa. I also do comparative research with the Primate Life History Database.
PhD in Biological Anthropology, 2014
University of Calgary
MA in Biological Anthropology, 2008
University of Calgary
BSc in Biology, 2002
California Institute of Technology
Adverse conditions in early life can have negative consequences for adult health and survival in humans and other animals. What variables mediate the relationship between early adversity and adult survival? Adult social environments represent one candidate: Early life adversity is linked to social adversity in adulthood, and social adversity in adulthood predicts survival outcomes. However, no study has prospectively linked early life adversity, adult social behavior, and adult survival to measure the extent to which adult social behavior mediates this relationship. We do so in a wild baboon population in Amboseli, Kenya. We find weak mediation and largely independent effects of early adversity and adult sociality on survival. Furthermore, strong social bonds and high social status in adulthood can buffer some negative effects of early adversity. These results support the idea that affiliative social behavior is subject to natural selection through its positive relationship with survival, and they highlight possible targets for intervention to improve human health and well-being.
Age-related changes in the capability to produce healthy young are common in humans and are increasingly well documented in nonhuman animals. However, differences among species in the nature of these age-related changes remain poorly understood. We compare patterns and consequences of age-related changes in female reproductive performance in seven primate populations that have been subjects of long-term continuous study for 29 to 57 y. Our analyses of parental age effects on fertility, offspring survival, and offspring development highlight some shared patterns of parental age effects that may be general across the order primates. At the same time, we also identify species-level differences that implicate behavioral and life-history patterns as drivers of the evolution of parental age effects.
Are differences in hypothalamic-pituitary-adrenal (HPA) axis activation across the adult life span linked to differences in survival? This question has been the subject of considerable debate. We analyze the link between survival and fecal glucocorticoid (GC) measures in a wild primate population, leveraging an unusually extensive longitudinal dataset of 14,173 GC measurements from 242 adult female baboons over 1634 female years. We document a powerful link between GCs and survival: Females with relatively high current GCs or high lifelong cumulative GCs face an elevated risk of death. A hypothetical female who maintained GCs in the top 90% for her age across adulthood would be expected to lose 5.4 years of life relative to a female who maintained GCs in the bottom 10% for her age. Hence, differences among individuals in HPA axis activity provide valuable prognostic information about disparities in life span. In wild female baboons, high fecal glucocorticoid concentrations measured repeatedly across adulthood predict shorter life spans. In wild female baboons, high fecal glucocorticoid concentrations measured repeatedly across adulthood predict shorter life spans.
People who are more socially integrated or have higher socio-economic status live longer. Recent studies in non-human primates show striking convergences with this human pattern: female primates with more social partners, stronger social bonds or higher dominance rank all lead longer lives. However, it remains unclear whether social environments also predict survival in male non-human primates, as it does in men. This gap persists because, in most primates, males disperse among social groups, resulting in many males who disappear with unknown fate and have unknown dates of birth. We present a Bayesian model to estimate the effects of time-varying social covariates on age-specific adult mortality in both sexes of wild baboons. We compare how the survival trajectories of both sexes are linked to social bonds and social status over the life. We find that, parallel to females, male baboons who are more strongly bonded to females have longer lifespans. However, males with higher dominance rank for their age appear to have shorter lifespans. This finding brings new understanding to the adaptive significance of heterosexual social bonds for male baboons: in addition to protecting the male’s offspring from infanticide, these bonds may have direct benefits to males themselves. This article is part of the theme issue `Evolution of the primate ageing process.’