Abstract:
We examine phylogenetic relationships among salamanders of the family
Salamandridae using approximately 2700 bases of new mtDNA sequence data
(the tRNA(Leu), ND1, tRNA(Gln), tRNA(Gln), tRNA(Met), ND2, tRNA(Trp),
tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr), and Cot 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. (c)
2006 Elsevier Inc. All rights reserved.
Authors:
Weisrock, David W.
Papenfuss, Theodore J.
Macey, J. Robert and
Litvinchuk, Spartak N.
Polymeni, Rosa
Ugurtas, Ismail H. and
Zhao, Ermi
Jowkar, Houman
Larson, Allan
