title: Higher-level relationships of caenophidian snakes inferred from four nuclear and mitochondrial genes.
abstract: Higher-level caenophidian snake relationships are inferred from sequence analyses of one nuclear gene (C-mos) and three mitochondrial genes (12S rRNA, 16S rRNA and ND4). Caenophidians, which are haenophidian closest relatives, have an Asiatic origin. An African clade comprising atractaspidids, psammophiines, 'lamprophiines' and 'pseudoxyrhophiines' is identified. We discern no evolutionary trend such as an improvement of the venom apparatus with a linear progression from the absence of a venom system to the presence of a front-fanged one. The venom apparatus is contemporary with the origin of colubroids and its absence in a few lineages results from secondary losses. The front-fanged venom system appeared three times independently. The active diurnal foraging mode (associated with a high metabolic rate) appears in a derived position among colubroids.
authors.affiliation: Service de systématique moléculaire, Institut de systématique (CNRS FR 1541), Muséum national d'histoire naturelle, 43, rue Cuvier, 75231 Paris, France. nvidal@mnhn.fr
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vidal
authors.forename: S Blair
authors.initials: SB
authors.lastname: Hedges
mesh_terms: D000825:Animal Structures / Q000033:anatomy & histology; D000818:Animals; D005075:Biological Evolution; D016384:Consensus Sequence; D004247:DNA / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics; D019143:Evolution, Molecular; D005796:Genes; D016258:Genes, mos; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011235:Predatory Behavior; D012335:RNA, Ribosomal / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012910:Snake Venoms; D012911:Snakes / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; C098483:NADH dehydrogenase subunit 4; D012335:RNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C075526:RNA, ribosomal, 12S; D012910:Snake Venoms; D004247:DNA; D009245:NADH Dehydrogenase