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A molecular phylogeny of four endangered Madagascar tortoises based on MtDNA sequences.
Mol Phylogenet Evol. 1999 Jun; 12(1):1-9.MP

Abstract

Four of the five tortoise species in Madagascar, Pyxis arachnoides, P. planicauda, Geochelone radiata, and G. yniphora, are endemic and on the verge of extinction. Their phylogenetic relationships remain controversial and unresolved. Here we address the phylogeny of this group using DNA sequences for the 12S and 16S rDNA and cyt b genes in mitochondrial DNA. As outgroups we used two species of Geochelone, pardalis (mainland Africa) and nigra (Galápagos), as well as a more distant North American tortoise, Gopherus polyphemus. We conclude that the two Pyxis species are sister taxa and are imbedded in the genus Geochelone, rendering this latter genus paraphyletic. There is moderate support for the sister status of the two Madagascar Geochelone and for the monophyletic origin of all four endemics, suggesting a single colonization of the island. The separation of Madagascar from other land masses (90-165 mya) predates the origin of the endemic tortoises (estimated to be 14-22 mya). This suggests founding by rafting, a process known to have occurred with other tortoises. The derived morphological divergence of the Pyxis species in a relatively short period of time (13-20 my) stands in contrast to the notoriously slow rate of morphological evolution in most lineages of Chelonia.

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Authors+Show Affiliations

Caccone A
Dipartimento di Biologia, II Università di Roma "Tor Vergata," Rome, 00175, Italy.
Amato G
No affiliation info available
Gratry OC
No affiliation info available
Behler J
No affiliation info available
Powell JR
No affiliation info available

MeSH

AnimalsDNA, MitochondrialEvolution, MolecularGenetic VariationPhylogenySequence Analysis, DNATurtles

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

10222157

Citation

Caccone, A, et al. "A Molecular Phylogeny of Four Endangered Madagascar Tortoises Based On MtDNA Sequences." Molecular Phylogenetics and Evolution, vol. 12, no. 1, 1999, pp. 1-9.
Caccone A, Amato G, Gratry OC, et al. A molecular phylogeny of four endangered Madagascar tortoises based on MtDNA sequences. Mol Phylogenet Evol. 1999;12(1):1-9.
Caccone, A., Amato, G., Gratry, O. C., Behler, J., & Powell, J. R. (1999). A molecular phylogeny of four endangered Madagascar tortoises based on MtDNA sequences. Molecular Phylogenetics and Evolution, 12(1), 1-9.
Caccone A, et al. A Molecular Phylogeny of Four Endangered Madagascar Tortoises Based On MtDNA Sequences. Mol Phylogenet Evol. 1999;12(1):1-9. PubMed PMID: 10222157.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - A molecular phylogeny of four endangered Madagascar tortoises based on MtDNA sequences. AU - Caccone,A, AU - Amato,G, AU - Gratry,O C, AU - Behler,J, AU - Powell,J R, PY - 1999/5/1/pubmed PY - 1999/5/1/medline PY - 1999/5/1/entrez SP - 1 EP - 9 JF - Molecular phylogenetics and evolution JO - Mol Phylogenet Evol VL - 12 IS - 1 N2 - Four of the five tortoise species in Madagascar, Pyxis arachnoides, P. planicauda, Geochelone radiata, and G. yniphora, are endemic and on the verge of extinction. Their phylogenetic relationships remain controversial and unresolved. Here we address the phylogeny of this group using DNA sequences for the 12S and 16S rDNA and cyt b genes in mitochondrial DNA. As outgroups we used two species of Geochelone, pardalis (mainland Africa) and nigra (Galápagos), as well as a more distant North American tortoise, Gopherus polyphemus. We conclude that the two Pyxis species are sister taxa and are imbedded in the genus Geochelone, rendering this latter genus paraphyletic. There is moderate support for the sister status of the two Madagascar Geochelone and for the monophyletic origin of all four endemics, suggesting a single colonization of the island. The separation of Madagascar from other land masses (90-165 mya) predates the origin of the endemic tortoises (estimated to be 14-22 mya). This suggests founding by rafting, a process known to have occurred with other tortoises. The derived morphological divergence of the Pyxis species in a relatively short period of time (13-20 my) stands in contrast to the notoriously slow rate of morphological evolution in most lineages of Chelonia. SN - 1055-7903 UR - https://www.unboundmedicine.com/medline/citation/10222157/A_molecular_phylogeny_of_four_endangered_Madagascar_tortoises_based_on_MtDNA_sequences_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1055-7903(98)90594-2 DB - PRIME DP - Unbound Medicine ER -