George N. Somero

Affiliated Researcher

Specialties: Climate Change Adaptation, Polar Research

George N. Somero was part of the team that developed the original proposal to create the Center for Ocean Solutions (COS). Somero received his Ph.D. from Stanford University. His group studies the effects of environmental factors – such as temperature, salinity, hydrostatic pressure and oxygen availability – on marine animals. Their studies of molecular evolution focus on macromolecular adaptations, for instance, changes in protein structure that underlie adaptive variation in functional properties and stability, and "micromolecular" adaptations which provide the appropriate intracellular milieu for macromolecular function. Studies of short-term responses to environmental change use DNA microarray technology to follow shifts in gene expression in marine organisms.

Adaptations in proteins play critical roles in allowing organisms to colonize habitats with temperatures ranging from Antarctic cold to hot-spring heat. Professor Somero's group has shown that adaptation in orthologous forms of enzymes involves amino acid substitutions that lie outside of the active site and which cause changes in conformational flexibility of the proteins. Adaptive variation may be achieved by only a single amino acid substitution in some cases. Temperature changes of only a few degrees Centigrade are adequate to favor selection for adaptive change, a finding that is relevant to concerns about global climate change.

In the context of climate change, studies of the thermal tolerance limits of such physiological processes as protein synthesis, induction of the heat-shock response, heart function and nerve conduction are showing that certain marine species may currently live near the upper limits of their thermal tolerance ranges. Species living at high temperatures, for instance, animals from the upper intertidal zone, seem less able to adapt to warming than related species found in cooler habitats, such as the subtidal zone. On-going studies are being conducted to reveal further aspects of the effects of global warming on marine species, in an attempt to allow predictions of how this warming may affect biogeographic patterning with latitude and along vertical gradients.

The physiology of invasive species is another focus of the laboratory. Physiological differences between native and invasive congeners of marine mussels are being studied in an attempt to define what makes a species a good invader and what environmental conditions may set the limits of the invasive process. Experimental approaches include heart physiology, gene-chip analysis of transcription and protein evolution.

Professor Somero received a Guggenheim Fellowship and is a member of the National Academy of Sciences and a fellow of the American Association for the Advancement of Science.

Members of Professor Somero's laboratory have joined faculties at the University of California at San Diego, University of California at Santa Barbara, University of California at Davis, Arizona State University, Purdue University, The University of Florida, the University of Colorado, the University of Miami, San Francisco State University, the University of San Diego, Louisiana State University, Ottawa University, the University of Southern California, the College of William and Mary, Cal Poly-San Luis Obispo and Whitman College.

Contact Information:
Email: somero@stanford.edu
Phone: (831) 655-6243
Website: http://www-marine.stanford.edu/somero.htm

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