oxidation of Fe +2 to Fe +3 drives reduction of SO 4 2- to H 2 S Microbes oxidize H 2 S to drive biochemical reactions
Hydrothermal Vents Communities A community whose primary energy source was not sunlight harnessed by photosynthesis, but chemical reactions Was this just the first community independent of sunlight?
The Ecological Theater and the Evolutionary Play G. E. Hutchinson Nothing in Biology Makes Sense Except in the Light of Evolution Theodosius Dobzhansky
Natural selection and adaptive evolution occur in the context of the environment. Within a species, genotypes are unevenly distributed among heterogeneous environments Species are sorted out by environmental variation, persisting in some environments, excluded from other environments
Patchy Occurrence of Species and Communities To what degree are species’ distributions limited by their adaptations environmental heterogeneity? pH? Temperature? F, NH 4, CH 4, H 2, H 2 S?
Henderson, Across a Drift D1D4 NH 4.006.112 SO 4 4.19.8 MN.662.84 ZN35155
A microbial survey of the anoxic water from 2025 D1. Microbial identifications are based of blast searches of 16 S rRNA sequences.
A microbial survey of the anoxic water from 2025 D4. Microbial identifications are based of blast searches of 16 S rRNA sequences.
Nitrogen NO 2 NO 3 NH 4 Where does it come from? Nitrospira Nitrospira oxides NO 2 to NO 3
A whole series of questions… What degree of isolation between surface and depth? Will water residence times increase with depth? To what degree are the communities influenced by the thermal gradient? To what degree do communities change with chemistry? Gene flow among environments? Gene flow overridden by selection? Unique, ancient lineages?