Nerve net Nerve net A nerve net consists of interconnected neurons lacking a brain or any form of cephalization. While organisms with bilateral body symmetry are normally associated with a central nervous system, organisms with radial symmetry are associated with nerve nets. Nerve nets can be found in members of the Cnidaria, Ctenophora, and Echinodermata phyla, all of which are found in marine environments. Nerve nets can provide animals with the ability to sense objects through the use of the sensory neurons within the nerve net. The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike
Branching order of bacterial phyla (Ciccarelli et al., 2006) is not monophyletic in this phylogram, but this may be erroneous given the large amount of literature in favour of basal Acidobacteria. Contrary to 16S trees, the deepest branching clade is the Firmicutes. Nevertheless, the last common ancestor was between Bacteria and Archaea+Eukarya. Branching order of bacterial phyla (Ciccarelli et al., 2006) There are several models of the Branching order of bacterial phyla, one of these was proposed in 2006 by Ciccarelli "et al." for their iTOL project. This tree is based on a concatenated set of conserved protein and not 16S rRNA (cf. Branching order of bacterial phyla (Woese,