Abstract

The ‘species problem’ can be characterized, to a first approximation, as the task of providing a viable species concept —that is, a functional analysis that picks out the ‘right’ kind of biological entities. After decades of debate and centuries of taxonomic practice, no overarching consensus has been reached. The individuation and definition of the units of evolution and classification, species included, remains controversial. If anything, there now seems to be more disagreement than ever before.