Concepts of species in trypanosomatids

This paper is a commentary on "Species concepts for trypanosomes: from morphological to molecular definitions?" by Wendy Gibson published in this journal [1]. Taxonomy has been traditionally based on expert opinion which is influenced among other factors by the philosophical and educational background of the expert concerned. This has resulted in widely different criteria for species among the trypanosomatids when compared to the actual genetic diversity involved. Gibson's paper presents an example of this within the trypanosome sub-genera. Although attempts have been made to put taxonomy on a more objective basis expert opinion still appears to dominate in the actual classifications in use.