Ignicoccus hospitalis (and its symbiote Nanoarchaeum equitans)
The eocyte hypothesis in evolutionary biology proposes that the eukaryotes originated from a group of prokaryotes called eocytes (later classified as Thermoproteota, a group of archaea).[1] After his team at the University of California, Los Angeles discovered eocytes in 1984,[2] James A. Lake formulated the hypothesis as "eocyte tree" that proposed eukaryotes as part of archaea. Lake hypothesised the tree of life as having only two primary branches: prokaryotes, which include Bacteria and Archaea, and karyotes, that comprise Eukaryotes and eocytes. Parts of this early hypothesis were revived in a newer two-domain system of biological classification which named the primary domains as Archaea and Bacteria.[3]
Lake's hypothesis was based on an analysis of the structural components of ribosomes. It was largely ignored, being overshadowed by the three-domain system which relied on more precise genetic analysis. In 1990, Carl Woese and his colleagues proposed that cellular life consists of three domains – Eucarya, Bacteria, and Archaea – based on the ribosomal RNA sequences. The three-domain concept was widely accepted in genetics, and became the presumptive classification system for high-level taxonomy, and was promulgated in many textbooks.[4][5]
Resurgence of archaea research after the 2000s, using advanced genetic techniques, and later discoveries of new groups of archaea revived the eocyte hypothesis; consequently, the two-domain system has found wider acceptance.[6][7]
^Archibald JM (December 2008). "The eocyte hypothesis and the origin of eukaryotic cells". Proceedings of the National Academy of Sciences of the United States of America. 105 (51): 20049–20050. Bibcode:2008PNAS..10520049A. doi:10.1073/pnas.0811118106. PMC 2629348. PMID 19091952.
^Lake JA, Henderson E, Oakes M, Clark MW (June 1984). "Eocytes: a new ribosome structure indicates a kingdom with a close relationship to eukaryotes". Proceedings of the National Academy of Sciences of the United States of America. 81 (12): 3786–3790. Bibcode:1984PNAS...81.3786L. doi:10.1073/pnas.81.12.3786. PMC 345305. PMID 6587394.
^Zhou Z, Liu Y, Li M, Gu JD (April 2018). "Two or three domains: a new view of tree of life in the genomics era". Applied Microbiology and Biotechnology. 102 (7): 3049–3058. doi:10.1007/s00253-018-8831-x. PMID 29484479. S2CID 3541409.
^Peirce SK (February 1999). "Three domains, not five kingdoms: A phylogenetic classification system". The American Biology Teacher. 61 (2): 132–136. doi:10.2307/4450634. ISSN 0002-7685. JSTOR 4450634. Archived from the original on 18 June 2024. Retrieved 16 May 2022.
^Forterre, P. (2015). "The universal tree of life: An update". Frontiers in Microbiology. 6: 717. doi:10.3389/fmicb.2015.00717. PMC 4508532. PMID 26257711.
^Nobs SJ, MacLeod FI, Wong HL, Burns BP (May 2022). "Eukarya the chimera: Eukaryotes, a secondary innovation of the two domains of life?". Trends in Microbiology. 30 (5): 421–431. doi:10.1016/j.tim.2021.11.003. PMID 34863611. S2CID 244823103.
^Williams TA, Cox CJ, Foster PG, Szöllősi GJ, Embley TM (January 2020). "Phylogenomics provides robust support for a two-domains tree of life". Nature Ecology & Evolution. 4 (1): 138–147. doi:10.1038/s41559-019-1040-x. PMC 6942926. PMID 31819234.
The eocytehypothesis in evolutionary biology proposes that the eukaryotes originated from a group of prokaryotes called eocytes (later classified as Thermoproteota...
as follows: The eocytehypothesis proposed in the 1980s by James Lake suggests that eukaryotes emerged within the prokaryotic eocytes. One piece of evidence...
collectively and culminated in the LUCA. In the eocytehypothesis, the organism at the root of all eocytes may have been a ribocyte of the RNA-world. For...
Heimdallarchaeota (an idea which is a modern version of the 1984 eocytehypothesis, eocytes being an old synonym for Thermoproteota, a taxon to be found nearby...
possibly evolved from prokaryotes. These results are similar to the eocytehypothesis of 1984, proposed by James A. Lake. The classification according to...
which formed the mitochondria; this hypothesis explains the genetic similarities between the groups. The eocytehypothesis instead posits that Eukaryota emerged...
modern nucleus; a prokaryotic cell (an archaeon according to the eocytehypothesis) which donated the cytoplasm and cell membrane of modern cells; and...
of Nitrososphaerota was thermophilic, and mesophily evolved later. Eocytehypothesis List of Archaea genera Oren A, Garrity GM (2021). "Valid publication...
presence of such genes support the hypothesis of an archaeal host for the emergence of the eukaryotes; the eocyte-like scenarios. Lokiarchaeota was introduced...
cycle and the nitrogen cycle. Thermoproteota (also called Crenarchaeota or eocytes) are a phylum of archaea thought to be very abundant in marine environments...