Tyler Evans

 

I am an environmental physiologist interested in using genomic tools to assess and predict the impact of global climate change on marine organisms.

 

My current research as a postdoc in Gretchen Hofmann’s lab at UCSB is aimed at assessing and predicting the impacts of two global climate change related factors:

 

1.) Ocean Acidification (OA): The chemistry of the world’s oceans is rapidly changing as a result of human combustion of fossil fuels. Approximately one-third of anthropogenic carbon dioxide (CO₂) is absorbed by the world’s oceans and with the progressive uptake of CO₂ waters become more acidic. Recent research has demonstrated that many ecologically and economically important marine species are negatively impacted by ocean acidification. Calcifying organisms that form carbonate hard parts appear to be especially vulnerable, as the acidic water make it more difficult to build their skeletons.

 

2.) Ocean Warming (OW): The rise in atmospheric temperature as a result of human activities is well-documented and by now familiar to most people. However, less prominent is the fact that temperatures within the world’s oceans are also increasing and average surface seawater temperatures are predicted to increase by anywhere from +1ºC to +6ºC by the year 2100. As temperature affects nearly every aspect of organismal function, shifts in ocean temperature regimes could have profound consequences for marine life.

 

Of critical importance to our understanding of the vulnerability of organisms to OA and OW is whether particular species currently possess the capacity to acclimatize to new environmental conditions.

 

 

The purple sea urchin (S. purpuratus) provides a powerful model for ocean change research. As an ecologically important marine calcifier found in relatively shallow water, S. purpuratus is anticipated to be affected by both OA and OW. Importantly, with the sequencing of the S. purpuratus genome, a powerful set of experimental approaches are now available to researchers. In this regard, I have used DNA sequence information to design a purple sea urchin microarray, a device that can be used to detect changes in gene expression that occur in response to shifts in temperature and pH. Modifying gene expression is central to maintaining cellular homeostasis in the face of environmental disturbances and the number and type of genes that are differentially expressed can tell us a lot about how urchins and other marine organisms are likely to respond to current and future ocean conditions.

 

 

Evans TG, Somero GN. (2010) Phosphorylation events catalyzed by major cell signaling proteins differ in response to thermal and osmotic stress in native (Mytilus californianus and Mytilus trossulus) and invasive (Mytilus galloprovincialis) species of mussels. Physiological and Biochemical Zoology. 83: 984-996.

 

Evans TG. (2010) Coordination of osmotic stress responses through osmosensing and signal transduction events in fish. Journal of Fish Biology. 76: 1903-1925.

 

Evans TG, Somero GN. (2008) A microarray-based transcriptomic time course of hyper- and hypo-osmotic stress signaling events in the euryhaline fish Gillichthys mirabilis: osmosensors to effectors. Journal of Experimental Biology. 211: 3636-3649.