Analysing disparity by applying combined morphological and molecular approaches to French and Japanese carabid beetles

The expression of morphological disparity within a clade is related to its history and to the environmental parameters within which it develops. Recen t developments in geometric morphometrics allow quantitative estimation of morphological disparity, and facilitate comparisons with genetic data inten ded to provide phylogenetic information. Such comparisons were made between two sets of ground beetle species from regions that differ biogeographical ly and environmentally: 12 post-glacial reinvading species from NE France; and 15 Japanese species less likely to be affected by the Pleistocene glaci al events. Genetic relationships were inferred from mitochondrial DNA (ND5 gene). Morphological divergences among the species were analysed using Proc rustes ver. 2.0, based on 64 landmarks (generalized analyses and computatio n of additive distance trees). The established morphospaces indicate distin ct disparity patterns in France and Japan, even though the genetic data sho w that neither of the two sets are monophyletic, and that they are in fact intermixed in the same clade. This discrepancy is partly related to the pre sence of extreme (elongated) morphologies in the Japanese set. But the stro nger disparity observed among Japanese species does not correspond to great er genetic differences. Those extreme morphologies appear to be related to the degree of endemicity of the species. The differences between the French and Japanese morphological patterns are discussed in the context of possib le geographic factors and climatic changes during the Pleistocene. (C) 2000 The Linnean Society of London.