Research overview
We are interested in understanding how global environmental changes such as urbanization and climate change affect the ecology and evolution of wild populations. This focus manifests in two primary areas of research in our lab: reproductive ecology and invasive species ecology and evolution. We use molecular ecology techniques such as DNA sequencing, genetic structure analyses, and genomic pedigree reconstruction to address our questions.
Reproductive ECOLOGYReproduction connects the environmental conditions experienced by the current generation with the genomic variation of the next generation, and consequently its ability to respond to environmental change. In the Levine Lab, we are interested in studying modes of reproduction that affect the longterm viability of populations, including facultative parthenogenesis, long-term sperm storage, and multiple paternity. We're interested in the relationship between the frequency of these reproductive modes in nature and the environmental conditions experienced by populations, as well as the effects of these reproductive modes on the strength of sexual selection and evolution occurring in these populations. We generally use reptiles as models for studying these topics, with a particular focus on snakes.
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Invasion ECOLOGY and evolutionInvasive species are those that are introduced (generally by people) to an area where they do not naturally occur that then spread and exert negative effects in their introduced environments. In this sense, invasions are a type of environmental change. We are interested in the intersection of invasive species with another type of environmental change: urbanization. We're currently exploring how urbanization affects the potential for future range expansion in invasive species through effects on invasive species evolution. We are using the invasive spotted lanternfly as a model system to explore these topics.
We also work at the intersection of reproductive ecology and invasive species. We're currently assaying for the presence of facultative parthenogenesis and long-term sperm storage in invasive brown treesnakes and studying mating system dynamics and sexual selection in invasive spotted lanternflies. |
current projects
Effects of Urbanization on the Evolutionary Dynamics
of Invasive Species Range Expansion Humans are rapidly changing the planet by building cities. Populations of invasive species (i.e., species that have been introduced to an environment where they do not naturally occur) that live in cities may evolve in response to urban conditions in ways that may cause them to spread faster and become harder to control. However, we do not yet know if invasive species in cities tend to evolve in particular directions due to higher urban temperatures (the "urban heat island effect") or if other factors like the genetic variation and connectivity of populations are more important. We are currently studying the population genomics of spotted lanternflies in rural and urban environments in their native range of China and two invasive ranges (USA and Japan) to understand how urbanization affects non-adaptive and adaptive evolution of invasive species as they spread. This project is funded by the National Science Foundation (NSF).
www.nsf.gov/awardsearch/showAward?AWD_ID=2312129&HistoricalAwards=false |
Spotted Lanternfly
Mating Dynamics and Sexual Selection
Although spotted lanternflies are ecologically and economically damaging, their abundance and ease of observation provides a rare opportunity to study fundamental questions in reproductive ecology and sexual selection. We have noticed that courtship events often involve one female and several males, and that females with more male suitors tend to attract even more male suitors. We are working on understanding mechanisms that drive the number of males courting a female, why some females are more attractive than others, what makes certain males more successful at courtship, whether males are competing for access to females, and whether post-copulatory sexual selection affects the resulting paternity. We're also interested in understanding how faster development in urban environments affects these dynamics.
Mating Dynamics and Sexual Selection
Although spotted lanternflies are ecologically and economically damaging, their abundance and ease of observation provides a rare opportunity to study fundamental questions in reproductive ecology and sexual selection. We have noticed that courtship events often involve one female and several males, and that females with more male suitors tend to attract even more male suitors. We are working on understanding mechanisms that drive the number of males courting a female, why some females are more attractive than others, what makes certain males more successful at courtship, whether males are competing for access to females, and whether post-copulatory sexual selection affects the resulting paternity. We're also interested in understanding how faster development in urban environments affects these dynamics.
Facultative Parthenogenesis and Long-Term Sperm Storage as Mechanisms of Establishment Success in Invasive Species
A critical question in invasion ecology is how invasive species become established when few individuals are introduced. Facultative parthenogenesis (asexual reproduction by females that normally reproduce sexually) and long-term sperm storage (storage of viable sperm from a previous mating event for an extended period in a female's reproductive tract) are two reproductive modes that may facilitate reproduction in the absence of mates in the initial stages of invasion. We are currently investigating whether facultative parthenogenesis and long-term sperm storage occur in the invasive brown treesnake by mining Dr. Brenna Levine's genomic pedigree of brown treesnakes on Guam.
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