The Hydrogen hypothesis is a model proposed by William F. Martin and Miklós Müller in 1998 that describes a possible way in which the mitochondrion arose as an endosymbiont within a prokaryotic host in the archaea, giving rise to a symbiotic association of two cells from which the first eukaryotic cell could have arisen (symbiogenesis).
According to the hydrogen hypothesis:
In 2015, the discovery and placement of the Lokiarchaeota (an archaeal lineage possessing an expanded genetic repertoire including genes involved in membrane remodeling and actin cytoskeletal structure) as the sister group to eukaryotes called into question particular tenets of the hydrogen hypothesis, as Lokiarchaeota appeared to lack methanogenesis. However, further examination revealed that Lokiarchaeota are indeed hydrogen-dependent, with evidence for methanogen-like metabolism outside of the euryarchaeotes.
See also
- Archezoa
- Eocyte hypothesis