2005 Fiscal Year Final Research Report Summary
Evolution in frontier environments
| Project/Area Number |
15340174
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | Tohoku University |
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Principal Investigator |
CHIBA Satoshi Tohoku University, Graduate School of Life Science, Associate professor, 大学院・生命科学研究科, 助教授 (10236812)
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| Co-Investigator(Kenkyū-buntansha) |
KASE Tomoki National Science Museum, Department of Geology, Chairman of the laboratory, 地学研究部, 室長 (20124183)
KAWATA Masakado Tohoku University, Graduate School of Life Science, Professor, 大学院・生命科学研究科, 教授 (90204734)
YAMASAKI Kazuhito Kobe University, Faculty of Science, Assistant professor, 理学部, 助手 (20335417)
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| Project Period (FY) |
2003 – 2005
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| Keywords | adaptive radiation / evolution / speciation / species diversity / morphology / mollusca |
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| Research Abstract |
Ecological and genetic process of adaptive radiation were examined using endemic land snail genus Mandarina of the oceanic Ogasawara Islands in the northwestern Pacific. Based on the habitat analysis, morphological analysis, and examination of the mitochondrial DNA sequence variations, we showed that hybridization between sympatric species occurred by alteration of habitat use due to environmental change. This suggests that speciation and adaptive radiation are still in progress in Mandarina. In addition, populations with unique shell morphologies were found in a hybrid zone constituted between morphologically closely related species. This suggests that hybridization is an important source of creating novel morphology and evolutionary novelty.
Phylogenetic relationship among the species of the land snails Euhadra in the mainland of Japan was estimated on the basis of mitochondrial DNA sequences. Repeated expansion and immigration have occurred in Euhadra, associated with climatic change during the Pleistocene. Complex spatial structure in genetic variations was created by mixing and isolation that were accompanied with the climatic change.
Relationship between intertidal gastropoda Batillaria cumingii and its parasites was examined on the basis of ecological, morphological and genetic (mitochondrial DNA and nuclear ITS gene) analysis. Genetic analysis revealed that these parasites include a large number of cryptic species. These species showed less geographical variations in genetic variations. On the other hands, Batillaria showed a high level of geographical variations in genetic components. Ecological speciation due to habitat shift would be a main cause of diversification of parasites in intertidal gastropoda.
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[Journal Article] Polymerase chain reaction-based restriction fragment length polymorphism and sequence analysis reveals cryptic species of trematodes in the intertidal gastropod2005
Author(s)
Miura, O., Kuris, AM., Torchin, ME., Hechinger, RF., Dunham, E., Chiba, S.
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Journal Title
International Journal for Parasitology 35
Pages: 793-801
Description
「研究成果報告書概要(和文)」より
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[Journal Article] Polymerase chain reaction-based restriction fragment length polymorphism and sequence analysis reveals cryptic species of trematodes in the intertidal gastropod2005
Author(s)
Miura, O., Kuris, A.M., Torchin, M.E., Hechinger R.F., Dunham, E.J., Chiba, S.
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Journal Title
International Journal for Parasitology 35
Pages: 793-801
Description
「研究成果報告書概要(欧文)」より
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