Overview
I am an evolutionary ecologist. I focus on studying evolution, particularly in insect popualtions, that occurs on time scales that can impact ecological processes. For example, the persistence of insect species under changing environments depends on whether or not the populations are able to adapt to the conditions present in their new habitats. However, competition for resources, habitat connectivity, and other ecological processes can also impact population survival and reproduction – these tradeoffs are what shape the field of evolutionary ecology.
My research focuses on the conservation and management of small or declining populations. I have used a small beetle, the red flour beetle (Tribolium castaneum), as a model system, as it can be very expensive and often logistically and ethically difficult to study these types of populations in the wild. Flour beetles are historic pests of stored grains such as wheat and rice, but they have been cultivated for use in experimental evolution studies for several decades because they are easy to rear and have a short life cycle, allowing for experiments that span multiple generations.
Members of the bug balers team: Adam O (R), me, Venkatesh P, and Katie H (L). Photo by Cody H (ARS).
"Beneficial Bug Balers": Conservation biological control
I am part of an interdisciplinary, dynamic team made up of researchers and technicians at the USDA-Agricultural Research Service, Colorado State University, and the University of Nebraska-Lincoln working to develop a biological control program for the wheat stem sawfly (Cephus cinctus). Sawfly contributes to over $350 million in crop losses annually, and traditional control methods such as insecticides are ineffective. Our team is working to introduce populations of the biocontrol agent, a native parasitoid wasp (Bracon spp.), on farms in Colorado and Nebraska using a program called the Beneficial Bug Balers. This involves transporting straw bales containing parasitoid to fields where the parasitoid is absent to help control the sawfly populations and minimize crop losses.
Population genetics of the clouded sulfur butterfly
I am collaborating with Kristen Ruegg's lab group to examine the population genetic structure and local adaptation of the Rocky Mountain clouded sulfur butterfly (Colias philodice eriphyle) in Colorado across high (>2500m) and low (<2000m) elevation sits using low coverage whole genome sequencing.
The manuscript is in preparation and my dissertation chapter is published on ProQuest.
A clouded sulfur butterfly (male).
Enlarged photo of Tribolium castaneum.
The impacts of gene flow on adaptation
I worked with red flour beetle microcosms (Tribolium castaneum) to study how gene flow (i.e., immigration or admixture) impacts adaptation in new and challenging environments. The introduction of new individuals into a declining population can help alleviate negative processes that impact small populations such as inbreeding, genetic drift, and demographic stochasticity. The potential increase in genetic diversity can also promote adaptation to novel environmental conditions (evolutionary rescue; see Durkee et al., 2023). However, gene flow can also can slow or prevent adaptation, particularly if the migrants are not adapted to the new environment (see Durkee et al., 2024). These trade-offs are important when considering management strategies like assisted migration or translocation for small or declining populations.
Past Work: Wetland Community Ecology
My undergraduate honors thesis focused on differences in benthic composition of a tidal, urban, freshwater marsh in Washington, DC. Specifically, I investigated the impacts of goose exclusion fencing on the macroinvertebrate community beneath areas where vegetation was present (fenced areas) vs. areas where vegetation was eaten by geese (unfenced areas). Flies, oligochaete worms, and nematodes were the most abundant taxa, which were able able to persist in higher densities in mudflat areas, and taxa diversity increased with the organic matter content of mud samples.
This work helped to inform the progress of restoration efforts and provided insights on invertebrate colonization patterns within the wetland.
Fenced experimental plots in Kingman Marsh in Washington, DC.