November 9 2010

12:00 BSRB 154

Ecolunch: Soren Faurby
Dept of Ecology and Evolutionary Biology, UCLA

Geographic variation in marine tardigrades and other microscopic organisms


The topic of this talk will be the existence and magnitude of geographic variation in microscopic organisms. The first part will focus on the existence of geographic differentiation. Some authors have claimed that the very large census population size of microscopic organisms automatically lead to large migration rates and thereby removes the potential for geographic differentiation. I will show with results from a meta-analysis of all genetic studies on microscopic marine organisms that this notion is not valid and that geographic differentiation is an important phenomenon in microscopic organisms, just as in macroscopic.
After this I will give a brief introduction to tardigrades and present my work on the tidal tardigrade genus Echiniscoides. I will show that on a global scale the distribution of individual species are limited by both ecological preferences and geographic barriers. Over evolutionary time, however, the geographic barriers does not appear to be unbreakable and speciation in the genus appear to be mainly along ecological gradients. On a regional level intraspecific analyzes of North Atlantic species show that a strong geographic structure is possible with the clearest cases of geographic differentiation associated with ocean barriers between North America and Greenland/ Iceland and between Greenland/ Iceland and continental Europe.
I will end with an introduction to my current project which focuses on geographic differentiation along the North American Pacific coast in order to understand the potential for differentiation along a continuous coast and the dispersal capacity of tidal tardigrades .















































































































































































































































































































































































































































































































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