The current controversy over the origin of modern humans, and the related arguments about the taxonomic affiliations of fossil groups of that genus, makes introducing this topic a challenge. I think it's easiest to name and describe the maximum number of proposed species and then show how various authorities lump them. Starting with the smallest number of species and then describing various schemes for splitting them would be confusing. It needs to be made clear, however, that this pedagogical decision does not necessarily indicate support for the model that recognizes 5 or 6 species or for the Recent African Origin hypothesis that follows from it. It is just the way I think best gets across the basic data. Then, in the next chapter, the controversy can be tackled in detail.
