A comparative test of a theory for disruptive selection on gamete size in marine green algae

2017 Fiscal Year Final Research Report

• Project/Area Number: 25257406
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 海外学術
• Research Field: Ecology/Environment
• Research Institution: Chiba University
• Principal Investigator: Togashi Tatsuya 千葉大学, 海洋バイオシステム研究センター, 教授 (70345007)
• Co-Investigator(Kenkyū-buntansha): 吉村 仁 静岡大学, 創造科学技術大学院, 教授 (10291957) ; 四ツ倉 典滋 北海道大学, 北方生物圏フィールド科学センター, 准教授 (60312344)
• Project Period (FY): 2013-04-01 – 2018-03-31
• Keywords: 異型配偶 / 性淘汰 / 性的二型

Outline of Final Research Achievements

Based on Parker, Baker and Smith’s theory (PBS theory) for the evolution of anisogamy, we tested disruptive selection on gamete size. We can expect that more strongly anisogamous species produce larger female gametes. Also, the relationship between the size of male gametes and the degree of anisogamy remains untested. In anisogamous species, the PBS theory predicts that male gametes are soon minimized in size. Because the evolution of isogamy with a gamete of zero size is favoured by selection there must be the minimum size of gametes. In such cases, the degree of anisogamy would not depend on the size of male gametes. We confirmed that, as the degree of anisogamy increases, the size of female gametes increases, and that in strongly anisogamous species, the degree of anisogamy does not depend on male gamete size. These results well support the PBS theory.

Free Research Field

進化生態学