2010 Fiscal Year Final Research Report

Influence of global warming on geographical cline of elytral colour polymorphism in the ladybird beetle, Harmonia axyrids

Research Project

Project/Area Number	20570026
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Ecology/Environment
Research Institution	Kyoto Sangyo University
Principal Investigator	NOMURA Tetsuro Kyoto Sangyo University, 総合生命科学部, 教授 (50189437)
Co-Investigator(Kenkyū-buntansha)	IWAISAKI Hiroaki 京都大学, 大学院・農学研究科, 教授 (00109042)
Project Period (FY)	2008 – 2010
Keywords	ナミテントウ / 鞘翅斑紋遺伝子 / 地理的勾配 / 地球温暖化 / 年代変化
Research Abstract	Natural selection has played a central importance in the explanation of adaptive evolution in organism. There have been, however, very few field evidences supporting the action of natural selection, compared to many fruitful results in artificial selection of domestic plants and animals. In this study, I investigated the geographical cline and its change over decades in the elytral colour polymorphism of the ladybird beetle,Harmonia axyrids, in Japan. In most of the sampling locations in Honsyu, Shikoku and Kyusyu islands, the frequencies of melanic genes increased, while the frequency of non-melanic gene decreased during the last several decades. The observed change in the gene frequencies coincided with the increase in the temperature in the reproductive season at most meteorological stations close to the sampling locations. These results could be a field evidence of micro-evolution by natural selection.