I am excited to build my laboratory and expand the hypotheses and models with which I have had the privilege to investigate. I am a marine evolutionary ecologist with an international reputation for improving our understanding of the impacts of seascapes and complex life cycle on marine population dynamics. In a broader context, the majority of my work utilizes organisms integral to global processes, such as primary production. I draw on my experience as both a field and molecular ecologist using natural history, manipulative field experiments and population genetic and genomic approaches to study a suite of marine biodiversity (e.g., invertebrates, ascidians, algae) and habitats (e.g., temperate rocky shores, mudflats, open ocean). I am looking forward to delving into adapting new molecular tools for organisms with complex life cycles to enable the study of genetic and phenotypic patterns in natural populations.
My research can be broadly defined by three, interwoven themes:
Connectivity: What are the patterns of gene flow across habitats and species? Population connectivity is central to marine ecosystem resilience. Unlike terrestrial ecosystems in which the subfield of landscape genetics is more advanced, there are severe knowledge gaps in the understanding of marine genetic structure. In the past few years, seascape genetics (the marine equivalent to landscape genetics) has made great strides in describing gene flow in the sea hitherto considered to be stochastic due to non-linear relationships between geographic distances and genetic differentiation. Comparatively little research has focused on the seascape genetics of organisms with more complex life cycles in which there are two free-living stages differing in ploidy levels. One of the major hallmarks of my research is the study of haploid-diploid algal population structure and gene flow. Marine algae are fundamental components of the global ecosystem through diverse processes, such as primary production, carbon transport, and the formation of three-dimensional structure and complexity in near-shore marine communities.
Life History Evolution: What factors underlie the maintenance of haploid-diploidy? My research provides evidence of metapopulation dynamics within the intertidal shorescape with core and marginal population dynamics, highlighting the role of marginal, high shore populations in the adaptive potential of these species to increasing environmental stress scenarios. For example, though sexual reproduction connects the haploid and diploid phases regardless of tidal height in the red seaweed Chondrus crispus, the pathogenic, endophytic alga Ulvella operculata may underlie the maintenance of haploid-diploidy. My dissertation was the first to demonstrate increased infection rates in male versus female gametophytes (with potential implications for the reproductive mode and mating system) as well as the correlation of infection rates with haploid-diploid ratios. Recently, I led a study in which the haploid-diploid life cycle was completely uncoupled during the invasion of novel habitats in the ubiquitous marine invader Gracilaria vermiculophylla. During the invasion of the Northern Hemisphere, this seaweed was primarily introduced to soft-bottomed habitats in which hard substratum is rare. Therefore, spores cannot easily recruit to the population. As a consequence, introduced populations have lost the free-living haploid stage.
Impact of Global Change on Marine Populations: How do populations respond to environmental perturbations? Over the course of the 20th century, sea levels rose in elevation, became warmer and more acidic, and biological invasions increased. These physical changes will continue to accelerate, significantly altering both near-shore and open-ocean ecosystems. It is difficult to ascertain whether marine populations will decline, experience range changes (e.g., shift poleward), or adapt in response to changing environmental conditions. I explore the impacts of environmental perturbations on marine populations using several approaches: (i) microevolutionary responses to climate change, (ii) macroecology, and (iii) biological invasions. I use models ranging from single-celled microalgae to ascidians (or sea squirts) to explore how global change will impact population dynamics in the marine environment.
Marine Evolutionary Ecology, Population Genetics, Molecular Ecology, Phycology, Scientific Communication
