Cohen Lab
Research Interests
We are interested in how ecological, behavioral, and environmental features shape evolution and genetic systems in diverse organisms. Most of our work in marine and estuarine settings has asked questions about how life history, physiological, or behavioral attributes of species affect population structure and how population structure may influence changes in life history traits.
Often the results of our research directly address questions about coastal and marine conservation related to our ability to detect, predict, and remediate anthropogenic effects on natural populations. This approach combining basic questions in ecology and evolution with applied issues in biology is carried out in pressing environmental situations that frequently feature non model taxa where methods development is also required. Thus, a signature feature of work in our lab is developing or adapting new field and laboratory methods to address environmentally relevant issues, often related to climate change. Some organisms and systems where this work is carried out including host/pathogen/symbiont interactions, seagrass restoration, sea star populations and wasting disease, endangered and endemic populations, invasive species and range extensions, and the impact of contaminants on local populations in estuarine settings.
In addition, we have a particular interest in the ecology and evolution of recognition systems. In vertebrates (fish, mice, and dolphins in our research), we use the immune recognition loci, the Major Histocompatibility Complex or MHC, to ask how high variability is maintained or lost under varying population conditions (both demographic and selective). In invertebrate chordates (aka tunicates or sea squirts), we make use of blood-mediated recognition loci that control colony fusion in the botryllid ascidians and gamete recognition loci in the solitary ascidian Ciona. We are additionally testing fusion genetics in the highly invasive didemnid ascidian Didemnum vexillum.
We have additional interests in systematics of sea stars and sea squirts (aka ascidians) and we work with the California Academy of Sciences and other museums to carry out morphological and molecular analyses related to global biogeography and systematics. The biotic diversity of the Philippines is a particular focus with ascidians as part of the NSF-funded Cal Academy Biotic Survey of the center of the center of marine biodiversity in the Verde Island Passage. Leptasterias systematics is a focus on the northeast Pacific coast related to shifting clade distributions prior to and following the recent epidemic of wasting disease.
For descriptions of a few projects, click below:
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EOS MOLECULAR LAB Find the seahorse and tunicate
Photo by Adriana Perez
Below you can find information on a few of the many subjects and projects we are interested in.
Biodiversity
May, RM, PLOS Biology, 2011, Why worry about how many species and their loss?
Conservation: The preservation and careful management of natural, and not so natural, habitats
EPA Cleanups: Communities around New Bedford Harbor
Invasive species
RESEARCH PROJECTS
Research Organisms
Inside a botryllid! Note the brooded embryos. Photo by Patrick Lee, SFSU undergrad.
Measuring leptasterias in the intertidal.