オサムシ類の体サイズの地理的変異 : 気候適応と種間相互作用がもたらすパターン

抄録

The geographic variation in body size of an insect species may reflect not only differential adaptation to local climatic conditions but also evolutionary consequences of interaction with closely related species. Thus, both intra- and interspecific body size variations need to be analyzed to understand evolutionary significance of geographic pattern of body size variation in a group of closely related species. Here, we introduce geographic patterns of intra- and interspecific body size variation in two groups of carabid beetles in Japan, Leptocarabus and Ohomopterus (the subtribe Carabina, Carabidae) and discuss the possible factors leading to the observed patterns. Body size of a species generally decreases with decreasing warmth of the habitat (the converse of the Bergmann's rule). However, coexisting related species at sympatric zones show separation in body size, leading to deviation from overall clinal trend of body size variation within species. Probably, interspecific interaction through reproductive interference at the secondary contacts has played a role in determining the combination of species that could coexist or affected the body size differentiation per se.