Habitat fragmentation and biodiversity: testing for the evolutionary effects of refugia

Concordant areas of endemism among taxa have important implications both for understanding mechanisms of speciation and for framing conservation priorities. Here we discuss the need for careful testing of phylogeographic data for evidence of such concordance, with particular reference to the Indonesian island of Sulawesi. This is because there are good reasons to question whether concordance between taxa is likely to be a common pattern, and because of the serious implications of incorrectly concluding that the biodiversity of a given area can be partitioned in this way.