Neomura is the domain containing the two subdomains of Archaea and Eukaryota. According to Thomas Cavalier-Smith, the distinction between Neomura and Bacteria was marked by twenty evolutionary adaptions, which accompanied, or derived from, two other important adaptions: the development of histones to replace DNA gyrase, and the loss of peptidoglycan cell walls to be replaced by other glycoproteins. The word "Neomura" reflects this last change; it means "new walls."
A phylogenetic tree, showing how Eukaryota and Archaea are more closely related to each other than to Bacteria
, based on Cavalier-Smith
's theory of bacterial evolution.