Divergence of species in the geothermal environment

Geothermal areas are unique in many aspects as microbial habitats. They are rare on a global scale and geographically confined. They can be regarded as islands, ecologically separated by large distances and physicochemical dispersal barriers. In a sense the global geothermal ecosystem can be considered to be a world of widely dispersed, often very different ‘archipelagos’ with no mainland. These and other features make geothermal sites an attractive and perhaps ideal model system for studies of microbial divergence and speciation. Microbial speciation may even be more easily observable in geothermal habitats than in other ecosystems.