Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)

  title={Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)},
  author={J C Ast},
  • J. Ast
  • Published 1 September 2001
  • Biology
  • Cladistics
Varanoidea is a monophyletic group of anguimorph lizards, comprising the New World helodermatids, the Bornean earless monitor Lanthanotus borneensis, and the Old World monitors (Varanus). I use mitochondrial DNA sequences and extensive taxonomic sampling to test alternative hypotheses of varanoid relationships. The most parsimonious hypothesis confirms the monophyly of Varanoidea (Heloderma, Lanthanotus, and Varanus) and Varanus, as well as the sister‐taxon relationship of Varanus and… 

Phylogeny And Systematics Of Squamata (Reptilia) Based On Morphology

This study examines squamate relationships using 222 ingroup taxa scored for 363 morphological characters and confirms the monophyly of the clades Scleroglossa (extant squamates exclusive of Iguania), Gekkota, Scincomorpha, Lacertoidea,ScincoideA, Anguimorpha and Varanoidea.

A combined evidence phylogenetic analysis of Anguimorpha (Reptilia: Squamata)

It is found that a global combined evidence analysis (GCA) does not recover a holophyletic Varanoidea, but omission of fossil taxa reveals cryptic molecular support for that group.

The Origin Of Varanus: When Fossils, Morphology, And Molecules Alone Are Never Enough

The landmass currently connecting Africa and Asia as well as the Lesser Sunda Islands in southern Wallacea may have facilitated intercontinental radiation of varanid lizards, which are distributed in Africa, Asia and Australia.

A molecular phylogeny for the Pacific monitor lizards (Varanus subgenus Euprepiosaurus) reveals a recent and rapid radiation with high levels of cryptic diversity

It is found that sympatry among species of Euprepiosaurus has not occurred until divergence times of 4.7–5.8 Myr have accrued, and Varanus jobiensis is a species complex with several divergent lineages that started to separate in the Pliocene and continued in the Pleistocene.

Molecular phylogenetics of squamata: the position of snakes, amphisbaenians, and dibamids, and the root of the squamate tree.

A molecular phylogenetic study of 69 squamate species suggests that similar states in Sphenodon and Iguania result from homoplasy, and species previously placed in Scleroglossa, Varanoidea, and several other higher taxa do not form monophyletic groups.

International Varanid Interest Group The Origin of Varanus : When Fossils , Morphology , and Molecules Alone Are Never Enough

It is considered that an integrated approach such as phylogeography might better explain the origin of this charismatic lizard group than any single analytical method.



Biogeographic origins of goannas (Varanidae): a molecular perspective.

The results suggest that the Australian species may be derived from an Asian source and are, therefore, in agreement with the hypothesis based on the fossil record suggesting that Varanidae may be Asian in origin.

Evolution of Body Size: Varanid Lizards as a Model System

Felsenstein's method of phylogenetically independent contrasts, coupled with information on branch lengths, is exploited to identify several likely instances of relatively rapid evolution of body size, both between and within clades.

Braincase and phylogenetic relationships of Estesia mongoliensis from the late Cretaceous of the Gobi Desert and the recognition of a new clade of lizards. American Museum novitates ; no.3211

It is revealed that Estesia mongoliensis is a member of a distinct clade of lizards including the extant Heloderma and its fossil relatives, and recognition of the new clade necessitates revision of the definition and diagnosis of the Helodermatidae.

Chromosomal evolution in the lizard genus Varanus (reptilia).

The most likely phylogenetic model based on chromosome morphology, fossil evidence and the current distribution of the genus Varanus is presented and is related to the current taxonomic groupings.

A Concern for Evidence and a Phylogenetic Hypothesis of Relationships among Epicrates (Boidae, Serpentes)

High levels of character congruence were observed among 89 biochemical and morphological synapomorphies scored on 10 species of Epicrates, and the consensus cladogram was consistent with the phylogenetic interpretation attached to the resulting hypothesis, which is a consensus of two equally parsimonious cladograms.

Aigialosaurs: mid-Cretaceous varanoid lizards

Aigialosaurs share many derived characters with modern varanids (including Lanthanotus and Varanus and the Eocene genus Saniwa), to the exclusion of the Upper Cretaceous varanid...

Molecular phylogenetics, tRNA evolution, and historical biogeography in anguid lizards and related taxonomic families.

Phylogenetic analysis of evolutionary changes in the gene encoding tRNA(Cys) suggests gradual reduction of dihydrouridine (D) stems by successive deletion of bases in some lineages, which contrasts with the one observed for parallel elimination of the D-stem in mitochondrial tRNAs of eight other reptile groups, in which replication slippage produces direct repeats.


Abstract Upper Cretaceous deposits at Ukhaa Tolgod and adjacent localities in the Mongolian Gobi Desert have yielded a large number of superbly preserved lizard specimens, including representatives

Multiple independent transpositions of mitochondrial DNA control region sequences to the nucleus.

  • M. SorensonR. Fleischer
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1996
The data suggest that the presumably nonfunctional but more slowly evolving nuclear sequences often will not be identifiable by changes incompatible with function and may be preferentially amplified by PCR primers based on mtDNA sequences from related taxa.