Members of my lab are currently working on several research projects. Our principle field site is in Costa Rica, but I collaborate with researchers working at field sites around the world. Our main areas of research are:
SENSORY AND FORAGING ECOLOGY:
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 (e.g., the “nocturnal visual predation” hypothesis), and shape the ecological niches of extant species. Through the integration of observational fieldwork, molecular ecology, metagenomics, stable isotope analysis 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.
Recent media coverage:
Detecting social signals may have affected how we see colors. ScienceDaily, Jun 14, 2017
Living a life in colour helps finding better food. The Science Breaker. July 3, 2017.
To Lions, Zebras Are Mostly Gray. So why are they stripey? Featured on TheAtlantic.com, Jan 2016.
Hidden Talents of the Colorbind. Animated Short Interview. Featured in the Ultra-Condensed Science Series. Sept 2, 2015.
Williams C. Many animals can still see colour in the dead of night. BBC Earth Dec 1, 2014.
Grens K. The Rainbow Connection: Color vision as we know it resulted from one fortuitous genetic event after another. The Scientist. Oct 1, 2014
HUMAN SENSORY ECOLOGY
Above: Mutwa man in Bwindi Impenetrable Forest National Park, Uganda. Photo credit: PJ Perry
The genetic basis of human sensory ecology remains poorly understood. Humans are unique among catarrhine primates in possessing frequent red-green color vision deficiencies, but the extent to which this reflects genetic drift versus selective advantage is unknown. Another common narrative in the literature on human sensation is that we have poor olfactory abilities compared to other primates. However, there is growing recognition that human olfaction is much better than previously believed and plays important roles in diet and reproduction. Available studies on the genes underlying color vision (opsins) and the chemical senses - olfactory receptor (OR) and taste receptor (TR) genes - reveal substantial variation between populations, with associated differences in sensory abilities, suggesting that human sensory phenotypes are plastic and responsive to local environments. Thus, a more important role of natural selection, versus neutral processes, in shaping sensory function may be operating in societies that search for resources. We are currently undertaking a collaborative, genomic-scale project on sensory variation among different human populations, including rainforest hunter-gatherers and agriculturalists in Uganda and the Philippines using targeted genomic sequencing. This work will robustly explore the links among foraging strategies and local environments in human sensory ecology, and shed light on the variables shaping sensory variation in hominin evolution.
Recent media coverage:
Johnston, Ian. 'Mismatch' between the way our senses evolved and modern world is making us ill, experts warn. The independent, Feb 20, 2017.
CAPUCHIN GENOMICS AND MICROBIAL ADAPTIONS TO DIET
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 gemone 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.
Recent media coverage:
Bugs may have made us brainy. Science News for Students. July 18, 2014.