That's "parsimonially correct" rather than "politically correct" in most
cases. Extremist cladists insist that all species are generated by a split
that ends an acestral species to create two new ones, each different from
each other and the ancestor. They reject a linear species sequence, such
as
H hablis-H erectus-H sapiens
but would accept
H hablis-------H erectus---H sapiens
\ \
H heidelburgensis H neandertalensis
Species do not necessarily behave in such a neat manner, so I think their
stance is unwarrented.
David Campbell