Research projects
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Ecological epigenetics of an ant-plant mutualism. All organisms in nature interact with other species. Managing these interactions - minimizing damage from antagonists, maximizing benefits from mutualists - often requires phenotypic plasticity, or change in phenotype without altering the underlying DNA sequence.
Phenotypic plasticity arises from changes in gene expression that are regulated by a number of molecular mechanisms. DNA methylation, the attachment of a methyl group to cytosine bases, is an epigenetic mark that is known to moderate induced responses to environmental cues. We are exploring patterns of DNA methylation associated with an obligate ant-plant mutualism in natural populations of Acacia drepanolobium at Mpala Research Centre in Laikipia, Kenya. This will help us understand how epigenetic and phenotypic variation arises and is maintained in natural populations, and how this diversity contributes to successful interactions with other species. |
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Population & ecological genetics of highly-selfing species. Self-pollination is the most extreme form of inbreeding, leading to highly homozygous genomes with extensive linkage. The American hogpeanut, Amphicarpaea bracteata, is almost exclusively selfing and is comprised of three homozygous, yet phenotypically variable, lineages. We are investigating questions about how these lineages are maintained and coexist in nature, especially in mixed-lineage populations; and how such invariant lineages are able to produce diverse phenotypes.
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Genetic diversity and adaptation in invasive species. From a population genetic perspective, biological invasions at first appear paradoxical: theory predicts that colonization events will reduce genetic diversity and limit adaptive ability. But invasive species are by definition extremely successful colonizers, and often do not display the predicted reduction in genetic diversity. We show how introduction history and life history traits, such as variation in mating patterns, can act to reduce loss of genetic diversity in colonizing (invasive) populations and how this affects their subsequent adaptation to their new environment.
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