Diet varies widely throughout the mammalian family tree, and several dietary specializations have evolved repeatedly both within closely related groups and between distantly related species. This combination of trait variation and repeated, or convergent, evolution, means that dietary traits represent great case studies for exploring how natural selection acts on genes involved in dietary specialization across multiple timescales. These studies may also provide insights into susceptibility to metabolic disease and other challenges to modern human society. We are currently investigating patterns of gene evolution associated with dietary changes across a set of over 200 mammals whose genomes have been sequenced.
This project involves the investigation of patterns of variation throughout human populations that are located near genes related to metabolism and digestion. We are looking to see whether or not there were any recent signatures of selection on these genes that could have possibly been caused by the population's diet. We analyze this population variation data using bioinformatics tools and several test statistics that can show signatures of selection compared to other populations.
This project aims to take a closer look at an invasive insect that is commonly found in Pennsylvania, New Jersey, and New York. The team is aiming to identify DNA extraction techniques that will provide high molecular weight DNA samples from the insect, which we -- or you! -- will then sequence using a small portable sequencing device. We plan to bring our genomics work on this species into the community and the classroom. If you are interested in working with us on this project, please contact us!
We are collaborating with other research groups performing work on the spotted lanternfly, including investigators at Cedar Crest College and Temple University.
Mammals have adapted to life underwater three different times: the closest relatives of cetaceans (dolphins, porpoises, and whales); pinnipeds (sea lions, seals, and walruses); and sirenians (manatees and dugongs) are all terrestrial. This spectacular transition from land to water led to a variety of changes in marine mammals’ bodies and genomes, including some changes that completely inactivated proteins. Often this happened to proteins that were essential in terrestrial mammals but either unnecessary or harmful in marine mammals: one example is a shared loss of smell in marine mammals, with the brain region responsible for smell completely absent in cetaceans. In my past work, I used data from 58 mammals' genomes to find cases where proteins lost their function repeatedly in different marine mammals, to identify candidate proteins whose importance changed when mammals went into the ocean.
One protein that shows this pattern is particularly interesting because it helps humans avoid getting sick from exposure to pesticides like chlorpyrifos. Working with collaborators who are experts in biochemistry and GPS mapping, I showed that losing this protein could be a big deal for manatees, which can be exposed to pesticides that run from farms into their canal and river habitats.
In order to understand what is going on in the genomes and environments of animals in the process of losing this important protein, my collaborators and I are also collecting data for semi-aquatic animals like beavers and muskrats, as well as for additional sea lions and their relatives that may not yet have fully lost protein function. Zooming in on the initial stages of loss in this way will help us to understand whether the loss is beneficial, as well as what genomic and environmental factors might be driving it.