The generation and maintenance of biodiversity is at the core of understanding how ecology and evolution interact. At the population level, biodiversity maintenance, and thereby evolutionary potential, involves balancing a combination of phenotypic and genetic diversity to minimize intraspecific competition yet maximize interspecific competitive advantage. Biodiversity studies often explore the genetic variation or phenotypic diversity across landscapes or gradients, but these studies often depict a population at a single point in its evolutionary history. Therefore, in order to understand the future maintenance of biodiversity, it is necessary to understand how genotypic and phenotypic diversity varies across time (repeat sampling), landscapes (from populations with no/limited gene flow), and gradients (variable ecological pressures). My dissertation research attempts to capture the effects that phenotype and genotype have on population dynamics and future evolutionary trajectories, as dimensions of intraspecific diversity.
I explore the relative importance of genetic diversity versus plasticity in stabilizing populations by examining life history traits—those traits directly related to fitness. This project focuses on populations of Daphnia ambigua, common freshwater microcrustacea, that experience different ecological and evolutionary constraints across a range of spatial and temporal environmental gradients, including strong seasonal predation and irregular ice cover. Life history trait variation is of utmost interest because of its high variability and low heritability, and I emphasized quantifying life history traits across environmental gradients and time scales. By combining demography, quantitative and population genetics, and systematics, my eco-evolutionary approach will help us understand how phenotype and genotype independently contribute to intraspecific variation and how their interaction affects population stability and persistence.
My projects aim to improve our understanding of how and why intraspecific variation is important for population persistence in variable environments and whether high genotypic diversity or high phenotypic plasticity alone is enough for population persistence, especially in light of global change.
Epischura baikalensis Population Genetics
The future of Lake Baikal’s biodiversity is uncertain in response to climate change. Unlike its diverse benthos, Lake Baikal’s zooplankton is species poor, with up to 96% of its biomass being composed of a single Calanoid copepod species, Epischura baikalensis.
This research characterized the genetic differentiation and differential gene expression of E. baikalensis. Using partial-transcriptome sequences obtained by 454 Rosche and Illumina sequencing technologies, the genetic differentiation at inferred single nucleotide polymorphism (SNP) sites and differential gene expression was examined in populations sampled from various parts of the lake were analyzed.
Daphnia Population Dynamics and Genetics
Much work has been done on the Connecticut lakes local to Yale, from the beginnings of community ecology with G E Hutchinson to the present by David Post’s lab, especially in regard to the Alewife. I am interested in characterizing the genetics, intraspecific variation, and dynamics of zooplankton populations in these lakes. I plan to use molecular techniques to answer questions about how genes transport through populations.
Especially pertinent to this system is the consequential secondary contact between landlocked Alewives (never go to the ocean) and anadromous Alewives (spend part of their lives in the ocean and part in inland waters). How these different populations react with secondary contact, having been separated for 100s of years, will impact the zooplankton populations in an unknown way, and I am interested in understanding how trophic level interactions effect population genetics.
Next Generation Science Standards and K-12 Education
While at ETSU, I was the recipient of the National Science Foundation’s Graduate K-12 Fellowship. Under this fellowship, I was challenged with bringing my genetics research to local pre-kindergarteners and kindergarteners.
As I became well-versed in the Tennessee State Science curriculum, I became interested in how Tennessee (and other states in the Southeast) would adapt and change to incorporate the new Next Generation Science Standards (2011), the suite of Science curriculum standards released by the National Research Council in tandem with the Common Core State Standards for Mathematics and English and Language Arts.
I spent a significant amount of time understanding how science is taught in the K-12 setting and how the NGSS would allow science curricula across the country to grow and develop over time.
Understanding best practices in relaying information from primary sources down to the K-12 setting is and will always remain an important motivation for my outreach and research.