title: Molecular phylogeny of the animal kingdom.
abstract: A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split gave rise to Platyhelminthes (flatworms) and the coelomate lineage. Coelomates are thus monophyletic, and they radiated rapidly into four groups: chordates, echinoderms, arthropods, and eucoelomate protostomes.
authors.affiliation: Institute for Molecular and Cellular Biology, Indiana University, Bloomington 47405.
authors.forename: K G
authors.initials: KG
authors.lastname: Field
authors.forename: G J
authors.initials: GJ
authors.lastname: Olsen
authors.forename: D J
authors.initials: DJ
authors.lastname: Lane
authors.forename: S J
authors.initials: SJ
authors.lastname: Giovannoni
authors.forename: M T
authors.initials: MT
authors.lastname: Ghiselin
authors.forename: E C
authors.initials: EC
authors.lastname: Raff
authors.forename: N R
authors.initials: NR
authors.lastname: Pace
authors.forename: R A
authors.initials: RA
authors.lastname: Raff
mesh_terms: D000818:Animals; D005075:Biological Evolution; D006801:Humans; D007448:Invertebrates / Q000235:genetics*; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D013045:Species Specificity
chemical_list: D012335:RNA, Ribosomal; D012337:RNA, Ribosomal, 18S