A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata).
We examine phylogenetic relationships among salamanders of the family Salamandridae using approximately 2700 bases of new mtDNA sequence data (the tRNALeu, ND1, tRNAIle, tRNAGln, tRNAMet, ND2, tRNATrp, tRNAAla, tRNAAsn, tRNACys, tRNATyr, and COI genes and the origin for light-strand replication) collected from 96 individuals representing 61 of the 66 recognized salamandrid species and outgroups. Phylogenetic analyses using maximum parsimony and Bayesian analysis are performed on the new data alone and combined with previously reported sequences from other parts of the mitochondrial genome. The basal phylogenetic split is a polytomy of lineages ancestral to (1) the Italian newt Salamandrina terdigitata, (2) a strongly supported clade comprising the "true" salamanders (genera Chioglossa, Mertensiella, Lyciasalamandra, and Salamandra), and (3) a strongly supported clade comprising all newts except S. terdigitata. Strongly supported clades within the true salamanders include monophyly of each genus and grouping Chioglossa and Mertensiella as the sister taxon to a clade comprising Lyciasalamandra and Salamandra. Among newts, genera Echinotriton, Pleurodeles, and Tylototriton form a strongly supported clade whose sister taxon comprises the genera Calotriton, Cynops, Euproctus, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Taricha, and Triturus. Our results strongly support monophyly of all polytypic newt genera except Paramesotriton and Triturus, which appear paraphyletic, and Calotriton, for which only one of the two species is sampled. Other well-supported clades within newts include (1) Asian genera Cynops, Pachytriton, and Paramesotriton, (2) North American genera Notophthalmus and Taricha, (3) the Triturus vulgaris species group, and (4) the Triturus cristatus species group; some additional groupings appear strong in Bayesian but not parsimony analyses. Rates of lineage accumulation through time are evaluated using this nearly comprehensive sampling of salamandrid species-level lineages. Rate of lineage accumulation appears constant throughout salamandrid evolutionary history with no obvious fluctuations associated with origins of morphological or ecological novelties.
Weisrock
David W
DW
Department of Biology, Box 1137, Washington University, Saint Louis, MO 63130, USA. weisrock@uky.edu
Papenfuss
Theodore J
TJ
Macey
J Robert
JR
Litvinchuk
Spartak N
SN
Polymeni
Rosa
R
Ugurtas
Ismail H
IH
Zhao
Ermi
E
Jowkar
Houman
H
Larson
Allan
A
D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012345:RNA, Transfer, Amino Acid-Specific / Q000235:genetics; D012356:RNA, Transfer, Leu / Q000235:genetics; D012455:Salamandridae / Q000145:classification* / Q000235:genetics*; D016415:Sequence Alignment
D004272:DNA, Mitochondrial; D012345:RNA, Transfer, Amino Acid-Specific; D012356:RNA, Transfer, Leu