Primates exhibit extensive variation in their sensory systems, which in turn influences how they perceive the world around them. Given that survival and reproduction are dependent on an individual's ability to find food, avoid predators, and find mates, differences in sensory perception have important fitness consequences. Accordingly, we expect these systems to be under strong selective pressure. My research integrates molecular, sensory, and behavioral ecology to identify variation in primate sensory systems and understand the evolutionary processes (both adaptive and nonadaptive) influencing this variation. My current projects focus on color vision in wild primates. Primate color vision represents a fairly well-established link between genotype and phenotype, and as such, is an ideal system for examining questions concerning selection and adaptation. Through multiple collaborations, I use genetic techniques to characterize color vision in lemur populations across Madagascar. I incorporate ecological (e.g., diet and habitat) and behavioral (e.g, foraging) data from these populations to address adaptive explanations for observed variation while also considering the potential role of nonadaptive processes (e.g., different demographic histories).
Variation in red-bellied lemur facial patterns (females above, males below)
Figure from Jacobs and Bradley 2016
Although much of my research has focused on how ecological pressures might shape variation in primate senses, differences in sensory perception likely influence the evolution of perceived stimuli. This may be particularly relevant for inter- and intra-specific signals in primates. Primates are remarkably variable in their skin and pelage patterns both across and within species (note the highly variable facial patterns of red-bellied lemurs to the right). Much of this variation may be related to conspecific recognition and mate selection, and is likely shaped by natural and sexual selection. My more recent research projects involve quantifying variation in primate skin and pelage patterns (e.g., color, size, shape) and identifying potential selective processes underlying this variation in light of differences in sensory perception.
Population and conservation genetics
I am broadly interested in measuring genetic variation and understanding how it is maintained and lost in natural primate populations. I incorporate analyses of neutral genetic markers to 1) examine social structure and patterns of gene flow, and 2) make inferences about past evolutionary events and processes (e.g., bottlenecks). Because these factors can influence the magnitude of genetic drift, this research can help us understand the relative importance of different evolutionary processes within and across populations. At the same time, information obtained from these studies can help identify at-risk populations and aid in conservation planning.