2021 Fiscal Year Final Research Report
Speciation driven by a cycle of secondary contact of related species and reproductive character displacement
Project/Area Number |
19H03286
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Review Section |
Basic Section 45030:Biodiversity and systematics-related
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Research Institution | University of the Ryukyus |
Principal Investigator |
Toda Mamoru 琉球大学, 熱帯生物圏研究センター, 准教授 (40378534)
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Co-Investigator(Kenkyū-buntansha) |
和智 仲是 琉球大学, 戦略的研究プロジェクトセンター, 特命助教 (40635299)
富永 篤 琉球大学, 教育学部, 准教授 (60452968)
城野 哲平 広島修道大学, 人間環境学部, 助教 (70711951)
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Project Period (FY) |
2019-04-01 – 2022-03-31
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Keywords | 生物多様性 / 種分化 / 爬虫類 / 両生類 |
Outline of Final Research Achievements |
Secondary contact of related species might lead reproductive character displacement (RCD) to avoid maladaptive hybridization. Because RCD occurs only in the sympatric populations, it induces character differentiation between sympatric and allopatric populations within a single species, that may further lead speciation. Successive speciation can be driven by a cycle of species’ dispersals, secondary contacts, and RCDs. We verified this hypothesis by use of groups of gecko and rice frog as models. Results showed that reproductive character difference was larger in the sympatric area than in allopatric area in several gecko species, being compatible with prediction deduced from the above hypothesis. However, such a character differentiation was not found in a case of secondary contact, negating the hypothesis. We also confirmed clear reproductive character difference between two rice frog species in parapatry, but failed to verify that this difference reflects character displacement.
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Free Research Field |
分類学,多様性生物学,爬虫類学,両生類学
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Academic Significance and Societal Importance of the Research Achievements |
繁殖形質置換の実証例は限られており,本研究の結果は,ヤモリ類において繁殖形質置換様のパターンが確認され,それが種分化の促進につながっている可能性を示した点で一定の意義がある.ただし,観察された変異の地理的パターンが実際に形質置換によるのか,仮に形質置換によっていたとしても,それと種分化との間に因果関係があるのかを明らかにするには至っておらず,今後,接触域と非接触域の詳細な比較・分析が必要である.本研究では,むしろ,ヤモリ類とヌマガエル類の分布と交雑の実態を明らかにし,種の分散と繁殖形質置換のサイクルによる玉突き的種分化仮説を検証する場を整えた点に大きな意味がある.
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