A study on the formation process of the Miyake's Line, a zoogeographic boundary between the Palaearctic and Oriental regions

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07528
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: The University of Tokyo
• Principal Investigator: YAGO MASAYA 東京大学, 総合研究博物館, 助教 (70571230)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 動物地理区 / 分布境界線 / チョウ類 / 生物地理 / 旧北区 / 東洋区 / 分子系統地理 / 自然史

Outline of Final Research Achievements

The Miyake's Line, which is located on the Osumi Strait between mainland Kyushu and the islands of Yakushima and Tanegashima, is considered to represent one of the zoogeographic boundaries between the Palaearctic and Oriental regions. Based on collected molecular and morphological data, we investigated the genetic structure and historical biogeography of several lepidopterans forming different faunas north and south of the Miyake's Line. Our results show that the lepidopterans that compose the northern fauna entered mainland Kyushu from the continent at various times such as about 0.5, 0.4, 0.17, 0.1 and 0.08-0.09 Mya, forming the present geographical distribution. On the other hand, most of the lepidopterans that compose the southern fauna may have formed the current distribution by expanding their distribution range toward the north, probably due to global warming and introduction in recent decades. Additionally, some species were taxonomically revised based on the analyses.

Free Research Field

昆虫自然史学、保全生物学

Academic Significance and Societal Importance of the Research Achievements

旧北区―東洋区間を隔てる動物地理区境界線の一つ「三宅線」を分布境界とするチョウ・ガ類について、形態による分類学的再検討と分子系統地理学的解析によってその遺伝的構造と形成過程を明らかにするとともに、各種で少しずつ異なる分化と多様化の成立要因を解明した。この成果は最近ではあまり注目されない三宅線の動物地理区境界線としての重要性を再認識させるとともに、多様性生物学の主軸である系統分類学や生物地理学、保全生物学への貢献だけでなく、分岐年代を伴う生物地理学的情報に地史や気候変動の情報を重ねて議論したことで、古地理学や古気象学にも寄与することが期待される。