Phylogeny, evolution, and biogeography of Asiatic Salamanders (Hynobiidae)

doi:10.1073/pnas.0602325103

Phylogeny, evolution, and biogeography of Asiatic Salamanders (Hynobiidae)

^†Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, Zhongshan University, Guangzhou 510275, People’s Republic of China;
^‡Department of Biology, Xinjiang Normal University, Xinjiang 830054, People’s Republic of China; and
^§Museum of Vertebrate Zoology, 3101 Valley Life Sciences Building, University of California, Berkeley, CA 94720-3160

Contributed by David B. Wake, March 22, 2006

Abstract

We sequenced 15 complete mitochondrial genomes and performed comprehensive molecular phylogenetic analyses to study the origin and phylogeny of the Hynobiidae, an ancient lineage of living salamanders. Our phylogenetic analyses show that the Hynobiidae is a clade with well resolved relationships, and our results contrast with a morphology-based phylogenetic hypothesis. These salamanders have low vagility and are limited in their distribution primarily by deserts, mountains, and oceans. Our analysis suggests that the relationships among living hynobiids have been shaped primarily by geography. We show that four-toed species assigned to Batrachuperus do not form a monophyletic group, and those that occur in Afghanistan and Iran are transferred to the resurrected Paradactylodon. Convergent morphological characters in different hynobiid lineages are likely produced by similar environmental selective pressures. Clock-independent molecular dating suggests that hynobiids originated in the Middle Cretaceous [≈110 million years ago (Mya)]. We propose an “out of North China” hypothesis for hynobiid origins and hypothesize an ancestral stream-adapted form. Given the particular distributional patterns and our molecular dating estimates, we hypothesize that: (i) the interior desertification from Mongolia to Western Asia began ≈50 Mya; (ii) the Tibetan plateau (at least on the eastern fringe) experienced rapid uplift ≈40 Mya and reached an altitude of at least 2,500 m; and (iii) the Ailao–Red River shear zone underwent the most intense orogenic movement ≈24 Mya.

Footnotes

^¶To whom correspondence may be addressed. E-mail: wakelab{at}berkeley.edu or lsbrc04{at}zsu.edu.cn
Author contributions: P.Z., D.B.W., and L.-H.Q. designed research; P.Z., H.Z., Y.-F.L., X.-L.W., and T.J.P. performed research; P.Z., Y.-F.L., X.-L.W., and T.J.P. collected samples; P.Z. and Y.-Q.C. analyzed data; and P.Z., D.B.W., and L.-H.Q. wrote the paper.
Conflict of interest statement: No conflicts declared.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. DQ333808–DQ333822).
Abbreviations:

Abbreviations:

Myr,

million years;

Mya,

million years ago;

ML,

maximum likelihood;

MP,

maximum parsimony;

NJ,

neighbor-joining.