Organisms of deep sea hydrothermal vents as a source for studying adaptation and evolution

It has been postulated that life originated in a similar environment to those of deep sea hydrothermal vents. These environments are located along volcanic ridges and are characterized by extreme conditions such as unique physical properties (temperature, pressure), chemical toxicity, and absence of photosynthesis. However, numerous living organisms have been discovered in these hostile environments, including a variety of microorganisms and many animal species which live in intimate and complex symbioses with sulfo-oxidizing and methanotrophic bacteria. Recent proteomic analyses of the endosymbiont ofRiftia pachyptila and genome sequences of some free living and symbiotic bacteria have provided complementary information about the potential metabolic and genomic capacities of these organisms. The evolution of these adaptive strategies is connected with different mechanisms of genetic adaptation including horizontal gene transfer and . various structural and functional mutations. Therefore, the organisms in this environment are good models for studying the evolution of prokaryotes and eukaryotes as well as different aspects of the biology of adaptation. This review describes some current research concerning metabolic and plausible genetic adaptations of organisms in a deep sea environment, usingRiftia pachyptila as model.