Neomura
| Neomura Temporal range: Neoproterozoic–Recent |
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| Eukaryotes and some examples of their diversity | |
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| Halobacteria, an Archaean genus | |
| Scientific classification | |
| Superdomain: | Neomura |
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Domain Archaea
Domain Eukaryota
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Neomura is a clade composed of the two domains of life of Archaea and Eukaryota. The group was first proposed by Thomas Cavalier-Smith and its name means "new walls"; so called because it is thought to have evolved from Bacteria, and one of the major changes was the replacement of peptidoglycan cell walls with other glycoproteins. The adjectival form is Neomuran, and a single individual from the group is called a Neomuran.
Thomas Cavalier-Smith states, "Eukaryotes and archaebacteria form the clade neomura and are sisters, as shown decisively by genes fragmented only in archaebacteria and by many sequence trees. This sisterhood refutes all theories that eukaryotes originated by merging an archaebacterium and an α-proteobacterium, which also fail to account for numerous features shared specifically by eukaryotes and actinobacteria."
The Neomura are a very diverse group, containing all of the multicellular species, as well as all of the most extremophilic species, but they all share certain molecular characteristics. All Neomurans have histones to help with chromosome packaging, and most have introns. All use the molecule methionine as the initiator amino acid for protein synthesis (Bacteria use formylmethionine). Finally, all Neomurans use several kinds of RNA polymerase, whereas Bacteria use only one.
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