INVASIVE SPECIES AS A MODEL FOR THE STUDY OF RAPID EVOLUTION
CASUAL SEMINAR IN BIODIVERSITY AND EVOLUTION
Invasive species often evolve rapidly in response to novel introduced environments, making them excellent models for the study of evolution. However, there remains an unsolved paradox: how can introduced populations that typically have low genetic diversity respond so quickly to selection? Is this response primarily based on novel mutations or are there other mechanisms (e.g. epigenetic modifications) through which rapid evolution is occurring in these systems? In this seminar, I will describe my research on rapid evolution in Australian invasive species and discuss future directions that aim to improve our knowledge of the fundamental mechanisms driving evolution during invasion. I will describe data from a range-edge population of invasive starlings (Sturnus vulgaris) in which we have found evidence of rapid evolution of mitochondrial DNA that is linked to changes in mtDNA copy number. I will also discuss changes in gene expression seen in invasive cane toad (Rhinella marina) muscle tissue from original sites of introduction in Australia compared to range-edge populations. We have now designed experiments to determine whether these changes in gene expression are related to genetic polymorphism or whether they are driven by differences in DNA methylation. The latter presents an exciting but controversial possibility: perhaps rapid evolution during invasion is often driven by environmentally induced epigenetic mechanisms.
Dr. Lee A. Rollings is broadly interested in the molecular ecology of invasive species, conservation genetics, avian behaviour, the genetics of social systems and how genes behave at a population level. Much of her work has focused on the role of dispersal in range expansions and the use of genetic analyses to understand contemporary population dynamics including rates of exchange between genetically separated populations. She is now investigating genes important to dispersal in order to examine the role of genetics in range expansion of invasive species.
[Host: Fernando Sequeira, Population Genetics, Hybridization and Speciation]
Image credits: https://jilldbarker.files.wordpress.com/2010/12/starling_adult1.jpg (Sturnus vulgaris); Paulo S. Bernarde (Rhinella marina)
