| Project/Area Number |
17570076
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Biodiversity/Systematics
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| Research Institution | Nagoya University |
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Principal Investigator |
KUMAZAWA Yoshinori Nagoya University, Graduate School of Science, Assistant Professor, 理学研究科, 講師 (60221941)
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| Co-Investigator(Kenkyū-buntansha) |
HASEGAWA Masami Research Organization of Information and Systems, The Institute of Statistical Mathematics, Professor, 統計数理研究所, 教授 (60011657)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Lacertilia / Iguania / Reptilia / Mitogenome / Continental drift / Biogeography / Molecular phylogeny / Mesozoic / ヤモリ下目 / 分岐年代 / トカゲ類 / ミトコンドリアDNA / マダガスカル |
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| Research Abstract |
Complete or nearly complete mitochondrial DNA sequences have been determined from various species of lizards that represent major families of the order Squamata. Together with previously published mitogenomic sequences of other vertebrate taxa, we have conducted molecular phylogenetic analyses. Reliable phylogenetic relationships have been established by the maximum-likelihood method and divergence times were estimated using a Baysian method without assuming the molecular clock. Biogeographic hypotheses were evaluated in light of these molecular results and independent geological and paleontological data Our major findings are the following. 1) Divergences between major lizard families predate the large-scale continental fragmentation during Cretaceous time, except for the divergence between Agamidae and Chamaeleonidae that likely occurred in the mid-Cretaceous. 2) On the other hand, most familial radiations of snakes postdate the Cretaceous/Tertiary boundary. 3) The break-up of Pangea into Laurasia and Gondwanaland may have been correlated with some shallower divergences of lizards, e.g., between Eublepharinae and Gekkoninae. Other findings include the first characterization of gene inversion in vertebrate mitochondrial geneomes in the proline tRNA gene of Draconinae agamids.
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