Abstract

Treating species as individuals and not classes has been crucial to the integration of evolutionary theory with modern systematics. Despite the theoretically important role the concept of individuality plays in modern phylogenetic systematics and in evolutionary theory more generally, many have been content to rely on common-sense intuitions about what counts as an individual. One of the most often cited intuitions is that individuals should be defined intrinsically. Unfortunately, common-sense intuitions like this one have proven to be inadequate for identifying and characterizing historical individuals (like species). An examination of real-world biological examples shows that our common-sense intuitions are equally inadequate when applied to at least some biological organisms--the paradigm individuals