Asgard Archaea & Complex Life
Archaea found from 2015 carry genes once thought unique to complex cells; a first cultured Asgard archaeon in 2020 supports a symbiotic origin of eukaryotes.
Open in the interactive tree →In 2015 a team led by Uppsala University described Lokiarchaeota, identified from DNA sampled at the Loki's Castle hydrothermal vent in the Arctic Ocean, as a new archaeal group related to eukaryotes. Asgard archaea carry proteins once thought to be exclusively eukaryotic, such as ESCRT complexes, ubiquitin systems and actin cytoskeletons. In January 2020 Hiroyuki Imachi's group in Japan reported Promethearchaeum syntrophicum, the first cultured Asgard archaeon, isolated from deep-sea sediment of the Nankai Trench after 12 years of work; its cross-feeding with bacteria and tentacle-like protrusions support the idea that an archaeal host engulfed the partner that became the mitochondrion. Analyses from 2022 to 2025 place eukaryotes deep within the Asgard group, as sister to the Hodarchaeales.
Prerequisites
- Evolution by natural selection1859
- Endosymbiosis1967Asgard archaea are tested as the host cell in the endosymbiosis that produced complex life
- Three domains of life1977They are placed on the tree of life that Woese's archaea discovery redrew
- Genome sequencing2003