Overview
My research focuses on understanding the biology, ecology, and evolution of freshwater mussels (Bivalvia: Unionida). This species-rich group of aquatic bivalves consists of over 800 species and can be found in lakes, rivers, and streams globally. My research is primarily performed on North America fauna, which is to the most diverse group of freshwater mussels on Earth with approximately 300 species. Broadly, I am interested in using genetic techniques to better understand the basic biology of freshwater mussels, life history traits driving diversification, the formation of species, and biological conservation. Phylogenetics
Life History Evolution Freshwater mussels have a compelling life cycle involving an obligate parasitic larval stage that requires temporary larval attachment to freshwater vertebrates (primarily fishes) to complete metamorphosis to a free-living juvenile. This life cycle has led to a rich diversity of life history strategies, which has heavily influenced the radiation of the group. In my lab, we use comparative phylogenomic techniques to better how life histories and associated traits contribute to the evolution of the group.
Systematics Although there has been a recent push into understanding the evolution of freshwater mussels, this group is still plagued by inaccurate systematics. Many cladistic hypotheses are still based solely on morphological characters, which has led to inaccurate classification across freshwater mussels. My lab uses integrative techniques incorporating ecological, geographic, molecular, and morphological datatypes to accurately infer evolutionary history and revise taxonomy accordingly. Conservation
Freshwater mussels are widely recognized as one of the most endangered groups of organisms on Earth, and the most imperiled group of organisms in the United States and Canada with over 70% of the fauna considered of conservation concern. Imperilment stems from a multitude of factors contributed by widespread anthropogenic habitat alteration to freshwater ecosystems, including deteriorating water quality, reduced water quantity, pollutants, and habitat which has resulted in extinctions of some species, extirpation of populations of other species, and reduction in density of most mussel populations. My lab uses population genetic techniques to help guide conservation strategies for these highly imperiled organisms. Doubly Uniparental Inheritance Mitochondrial DNA is almost always strictly maternally inherited. However, bivalves, including freshwater mussels, possess a unique mode of mt inheritance called doubly uniparental inheritance (DUI). This phenomenon involves the transmission of two mt genomes—one of which is passed by females through the eggs to all offspring and a second that is passed by males through sperm only to their sons. By using genomic techniques, my lab is actively investigating mitonuclear interactions and the contribution of sex-biased mitochondria to sex determination in freshwater mussels. Genomic Resources
The availability of genomic resources are lacking for not only freshwater mussels, but nearly all bivalve lineages. In my lab, we use modern molecular methodologies to establish high quality genomic resources for freshwater mussels that are pivotal to test evolutionary hypotheses regarding the basic biology of these organisms. |