The Science Seminar Series: March 8, 2012
Evolution in a changing world: Insight from phenotypic strategies and marine larvae
Dr. Justin McAlister
Department of Biology
Time: 4:00 -5:00pm
My research interests straddle the interface of organismal and population biology with the marine sciences and ecotoxicology. I am broadly interested in the expression and evolution of morphological and physiological phenotypes in response to natural and anthropogenic environmental change, how these responses vary among taxa, shape the evolution of life histories, the mechanisms that underlie their expression, and I work primarily with marine invertebrates and their larvae. I will present the results of research examining how historical environmental changes in phytoplankton food levels have led to changes in the two primary means by which marine invertebrate larvae acquire and utilize the structural and energetic materials required for metabolism and morphogenesis: (1) by using their own food collection structures to capture exogenous phytoplankton, and/or (2) by utilizing the endogenous biochemical constituents provided to them by their mothers in the egg (the single most important cell in an organism’s life cycle). For these studies, I have been examining the eggs and larvae of tropical echinoderm “geminates,” closely related species that were separated ~3.2 million years ago during and subsequent to the rising of the Isthmus of Panama. These organisms now inhabit marine oceanic environments, the tropical western Atlantic and eastern Pacific, that differ markedly in primary productivity and phytoplankton food availability. Trans-isthmian geminate species offer a unique replicated natural research system that can be used to examine the ecological and evolutionary ramifications of large-scale environmental changes.