title: Hexapod origins: monophyletic or paraphyletic?
abstract: Recent morphological and molecular evidence has changed interpretations of arthropod phylogeny and evolution. Here we compare complete mitochondrial genomes to show that Collembola, a wingless group traditionally considered as basal to all insects, appears instead to constitute a separate evolutionary lineage that branched much earlier than the separation of many crustaceans and insects and independently adapted to life on land. Therefore, the taxon Hexapoda, as commonly defined to include all six-legged arthropods, is not monophyletic.
authors.affiliation: Department of Evolutionary Biology, University of Siena, via Aldo Moro 2, 53100 Siena, Italy. nardifra@unisi.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Nardi
authors.forename: Giacomo
authors.initials: G
authors.lastname: Spinsanti
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Boore
authors.forename: Antonio
authors.initials: A
authors.lastname: Carapelli
authors.forename: Romano
authors.initials: R
authors.lastname: Dallai
authors.forename: Francesco
authors.initials: F
authors.lastname: Frati
mesh_terms: D000818:Animals; D001181:Arthropods / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D001482:Base Composition; D005075:Biological Evolution; D003445:Crustacea / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D007313:Insecta / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial