Process of species diversification in fossil records of land snails on remote islands

• Project/Area Number: 15H03743
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: Tohoku University
• Principal Investigator: Chiba Satoshi 東北大学, 東北アジア研究センター, 教授 (10236812)
• Research Collaborator: HIRANO Takahiro ; MORII Yuuta ; Prozorova Larisa ; SUZUKI Takanori
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2017: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2016: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2015: ¥6,760,000 (Direct Cost: ¥5,200,000、Indirect Cost: ¥1,560,000)
• Keywords: 進化 / 海洋島 / 生物地理 / 更新世 / 適応放散 / 種分化 / 島嶼 / 生態学 / 生態系修復 / 陸貝 / 層位・古生物学 / 系統進化 / 多様化 / 多型

Outline of Final Research Achievements

A rapid morphological and ecological divergence was documented in the fossil records ofland snails in the Pleistocene and Holocene deposits on the Ogasawara Islands.　However, such rapid divergence is not found in the fossil snail sequences in the Ryukyu Islands (e.g. Kikai Island). Molecular phylogenetic analyses and ecological surveys showed consistent relationships among morphology, ecology and phylogeny were found in Ogasawara, Ryukyu, and mainland lineages, but rapid ecological and species divergence are limited to the snails of Ogasawara. These patterns are consistent with those detected in the fossil records. Divergence of habitat use promoted by competitive interaction appears to be a major process of speciation and radiation on oceanic islands, while speciation on mainland occurs by adaptation against predation as well as geographic isolation.

Research Products

• [Int'l Joint Research] ロシア科学アカデミー(ロシア連邦)
• [Journal Article] Genetic and morphometric rediscovery of an extinct land snail on oceanic islands. (2018)
  • Author(s): Hirano, T., Wada, S., Mori, H., Uchida, S., Saito, T., & S Chiba
  • Journal Title: Journal of Molluscan Studies Volume: 84 Issue: 2 Pages: 148-156
  • DOI: 10.1093/mollus/eyy003
  • Peer Reviewed
• [Journal Article] Single-gene speciation : mating and gene flow between mirror-image snails. (2017)
  • Author(s): Richards, P.M., Morii, Y., Kimura, K., Hirano, T., Chiba, S., & Davison, A.
  • Journal Title: Evolution Letters Volume: 1 Issue: 6 Pages: 282-291
  • DOI: 10.1002/evl3.31
• [Journal Article] Evolution and extinction of land snails on oceanic Islands. (2016)
  • Author(s): Chiba, S., Cowie R.H.
  • Journal Title: Annu. Rev. Ecol. Evol. Syst. Volume: 47 Issue: 1 Pages: 123-141
  • DOI: 10.1146/annurev-ecolsys-112414-054331
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Formin is associated with left-right asymmetry in the pond snail and the frog. (2016)
  • Author(s): Davison A., McDowell G.S., Holden J.M., Johnson H.F., Koutsovoulos G.D., Liu M.M., Hulpiau P., Van Roy F., Wade C.M., Banerjee R., Yang F., Chiba S., Davey J.W., Jackson D.J., Levin M., Blaxter M.L.
  • Journal Title: Current Biology Volume: 26 Issue: 5 Pages: 654-660
  • DOI: 10.1016/j.cub.2015.12.071
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Dynamics of evolutionary radiation under ecological neutrality. (2016)
  • Author(s): Suzuki, T., Chiba, S.
  • Journal Title: Journal of Theoretical Biology Volume: 406 Pages: 1-7
  • DOI: 10.1016/j.jtbi.2016.06.006
  • Peer Reviewed
• [Journal Article] Effects of an invasive ant on land snails in the Ogasawara Island (2016)
  • Author(s): Uchida S., Mori H., Kojima T., Hayama K., Sakairi Y., Chiba S.
  • Journal Title: Conservation Biology Volume: 30 Issue: 6 Pages: 1330-1337
  • DOI: 10.1111/cobi.12724
  • Peer Reviewed
• [Journal Article] Parallel evolution of passive and active defence in land snails. (2016)
  • Author(s): Morii Y., Prozorova L., Chiba S.
  • Journal Title: Scientific Reports Volume: 6 Issue: 1
  • DOI: 10.1038/srep35600
  • NAID: 120005898498
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Divergence in the shell morphology of the land snail genus Aegista. (2015)
  • Author(s): Hirano, T., Kameda, Y., Kimura, K., Chiba, S.
  • Journal Title: Biological Journal of the Linnean Society Volume: 114. Issue: 1 Pages: 229-241
  • DOI: 10.1111/bij.12407
  • Peer Reviewed
• [Journal Article] A new species in the genus Aegista from Chugoku district, Japan (Gastropoda: Heterobranchia: Stylommatophora: Camaenidae) (2015)
  • Author(s): Hirano, T., Kameda, Y., Chiba, S.
  • Journal Title: Molluscan Research Volume: 35 Issue: 2 Pages: 128-138
  • DOI: 10.1080/13235818.2015.1023175
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Evidence of introgressive hybridization between the morphologically divergent land snails Ainohelix and Ezohelix (2015)
  • Author(s): Morii, Y., Yokoyama, J., Kawata, M., Davison, A., Chiba, S.
  • Journal Title: Biological Journal of the Linnean Society Volume: 115 Issue: 1 Pages: 77-95
  • DOI: 10.1111/bij.12466
  • Peer Reviewed
• [Presentation] Adaptive and non-adaptive radiation in island snails (2017)
  • Author(s): Chiba, S.
  • Organizer: 個体群生態学会
  • Invited