Dr. Amanda Melin

Recent research on the human microbiome has demonstrated a strong effect of diet, environment and health on the gut microbiota, raising the possibility that this relationship extends to other primates. However, little is known about how changing environments, accompanied by pronounced dietary shifts, affects the microbiome and shapes digestive adaptations. Ongoing advances in massive parallel sequencing are continually increasing our ability to ask refined, detailed question of wild populations. We are conducting a fecal metagenomic study spanning the seasonal transitions in Santa Rosa, Costa Rica to identify the taxonomic composition and functional genomes of the resident intestinal microbiota of capuchin monkeys and reveal how shifts in climate and diet impact these symbiotic organisms. We are additionally assembling a genome reference for white-faced capuchin monkeys that will assist in this project and be broadly useful in comparative primate genomics. Together, this information will reveal how omnivorous primates manage the varied digestive challenges of their eclectic diet, and adapt to the profound seasonal shifts in food availability.

Eyesight is used throughout modern life, and large resources are leveraged to mitigate eye diseases. We integrate transcriptomic, metabolomic, and genomic data with corresponding measures of ocular health (ophthalmological exams, including optical coherence tomography) and visual function (behavioural looking time experiments) in rhesus macaques on Cayo Santiago, Puerto Rico, to investigate impacts of age and genomic background on glaucoma, age-related macular degeneration, retinal detachment and other eye diseases. In a complimentary line of research in the same study system, we examine the variation and heritability of M and L cones underlying red-green colour vision using behavioural measures of colour discrimination and opsin gene expression to probe the cone ratios. In both cases, a deep pedigree facilitates examining heritability and impact of the genomic environment on visual variation.

Current Collaborators: James Higham (New York University), John Danias (SUNY Downstate), Gadi Wollstein (New York University Langone), Melween Martinez (University of Puerto Rico), Shoji Kawamura (University of Tokyo)

Through their senses, animals interface with the environment to find food, select mates, and avoid predators. The interrelationships among diet, activity pattern and the senses are central to hypotheses of primate origins and adaptive radiation and shape the ecological niches of extant species. Through the integration of observational fieldwork, genetics and genomics, and computer models of animal vision, we seek to understand the adaptive complexes of primates, including humans, using an innovative and multidisciplinary approach. Our research centers around: 1) intra- and interspecific color vision variation in primates and other mammals with functional and phylogenetic relevance to primate origins and adaptive radiation (treeshrews, fruit bats, opossums); 2) variation within and between species in diet and use of sensory behaviors (e.g. touch, sniff, lick) while foraging, with the goal of linking behavioral variation to sensory genotypes; and 3) the visual, olfactory, gustatory and mechanical cues of food quality, with the goal of identifying important cues that shape the sensory systems of consumers.

Current Collaborators: Shoji Kawamura (University of Tokyo), Carrie Veilleux (Midwestern University), Nathanial Dominy (Dartmouth College), and Mrinalini Watsa (Field Projects International, San Diego Zoo)

Chronological age is a strong predictor of health and lifespan, yet the process of biological aging unfolds at different speeds among individuals. While some individuals maintain good health well into their advanced years, others experience age-related diseases at a relatively young age. Although there is still much to unravel regarding the diverse progression of human aging, a growing body of literature emphasizes the significance of both social and physical environments in this regard. The study of human health and the rate of aging encounters limitations due to the challenges associated with gathering comprehensive longitudinal data on personal experiences and health outcomes. Additionally, human studies are complicated by various confounding factors such as differences in lifestyle, early-life encounters, and access to healthcare. In contrast, investigations involving nonhuman primates living in the wild offer invaluable insights into the influence of social and physical environmental factors on natural aging processes and human healthspan.

In our project, we leverage our established long-term study on wild, white-faced capuchins (Cebus imitator) to enhance our comprehension of how social and physical environmental factors contribute to variations in aging rates and disparities in health. We are developing innovative methods for non-invasive, population-level sampling of wild animals, enabling us to identify and examine aging hallmarks across behavioural, physiological, and molecular domains. By studying the physical health of capuchins in their natural habitat and combining it with our extensive dataset on their lifetime social and environmental experiences, we can holistically evaluate the impact of personal and intergenerational encounters on health outcomes and the pace of aging among individuals.

Principal Investigator: Dr. Amanda Melin, Dr. Fernando Campos, and Dr. Katharine Jack
Co-Investigators: Dr. Michael Gurven, Dr. James Higham
Collaborators: Dr. Joe Orkin, Dr. Eva Wikberg, Dr. Yeonjoo Park
Consultant: Dr. Noah Synder-Mackler