Our focus is on basic ecological and evolutionary research, with application to contemporary issues such as conservation biology, invasive species, marine protected areas, and global change:
i. Long-term ecological and evolutionary studies of community assembly and dynamics
ii. Systematics, biogeography, ecology, and evolution of scyphozoan jellyfishes
iii. Comparative population genomics of intertidal invertebrates
iv. Population genomics of Mastigias jellyfishes
v. Island biogeography, ecology, & evolution
vi. Marine, terrestrial, freshwater, aerial comparisons & contrasts
General opportunities for undergraduate experience in my lab are outlined on the undergraduate information page.
Options for a graduate career in my lab are outlined on the graduate information page
Ongoing openings for postdocs are described on the post-doc information page.
"Selection and genetic succession in the intertidal – population genomics of Pisaster ochraceus during a wasting disease outbreak and its aftermath"
NSF Biological Oceanography OCE-1737381
PI: Mike Dawson (UC Merced)
Co-PIs: Ian Hewson (Cornell), Pete Raimondi (UC Santa Cruz), & John Wares (U. Georgia, Athens)
Postdoc: Lauren Schiebelhut
Graduate student: Starting Fall 2018.
Understanding the consequences of large-scale pandemics in the broader contexts of geographic heterogeneity and chronic changes in ocean pH and temperature is an emerging contemporary issue. This project employs long-term characterization of population dynamics and genetic consequences of a sea star wasting disease (SSWD) outbreak, which caused median 90% mortality in Pisaster ochraceus populations in the northeastern Pacific, to estimate potential long-term consequences for the species. While the largest recorded influx of new recruits occurred in 2014-2016, it is unknown where they originated from, whether recruits and surviving adults remained susceptible to the disease, which persisted at low levels, and for how long these dynamics might continue. Our long-term dataset provides a unique opportunity for exploring the short and long term repercussions of such large-scale disease outbreaks and the population dynamics that they precipitate. This project builds on long-term field studies of wild populations to describe host population dynamics, the disease, and genomic diversity. The goal is to discover genetic variation associated with SSWD and to dissociate that variation from population genomic effects attributable to abiotic environmental variation. Objectives are: (1) Census P. ochraceus at 24 sites throughout its range to describe population dynamics, the prevalence of SSWD, and measure abiotic variables. (2) Conduct laboratory experiments coupled with RNAseq analyses to determine loci differentially regulated during exposure to SSWD, temperature, salinity, and pCO2 anomalies. (3) Map ddRAD, RNAseq, and candidate loci under selection to a P. ochraceus genome. (4) Conduct range-wide population genomic analyses for 3 years to assess genetic (SNP) variation among wild-caught specimens with, versus without, SSWD across a geographic mosaic of abiotic variation. (5) Explore links between SSWD and candidate loci, such as EF1A. These analyses will describe the immediate genomic consequences of the disease outbreak, the population dynamics that the outbreak set in motion, and the interplay of factors and mechanisms—such as disease, temperature, migration, selection—that effected these changes. The results will advance understanding of general processes and interactions that shape population genomic structure in coastal ecosystems, providing resources to inform future research and applications in design of management strategies for coastal living resources.