Biologists like S.J.Gould went to great lengths to criticize the arrogance in progressivist views of evolution, but unfortunately, although his eloquent views should stand as part of a debate, he didn’t really win the argument. The reason is simple: darwinian views of random evolution don’t properly explain what the record in deep time shows. But here noone really has the right theory, including the critics of darwinism.
IN WHEE, fourth edition, a very short take on this question is given, at the start of Chapter 4: the stream and sequence concept, not designed for the data of deep time, but still roughly relevant, suggests that we can’t see evolutionary progression because evolution operates on two levels and we tend to see only the level of proliferation which is roughly ‘random’ in its action. The point is that one level is producing macro advances while the lower level is sort of micro and far more visible to us.
The point is the suspicion that, not progress necessarily, but progression is an aspect of evolution and this operates to create a new plateau at each relevant stage, each of these being a theatre of complex proliferation. In any case we need to have a really adequate theory of human evolution here, and we don’t.