Darwin didn't dispose of the idea of two sexes, nor did he blur the line between species in general. His theory blurred the line between man and nature - taking humans from their place as special creations of God and firmly placing them in the natural world. — Harry Hindu
Good point. The argument between Conservatives (religious & political) and Progressives seems to be about the scientific deconstruction of what one side views as a proper & fitting Natural Hierarchy, not just of sexes, but of species and various other demarcations of reasonable categories. The conservative side seems to prefer simple authoritative distinctions (special creation), while progressives prefer some leeway to interpret those classifications as they see fit. That may be why, as I said in the OP, my brief online review turned-up far more objections to the concept of continual evolution from a conservative perspective.
[note : I'm neither conservative nor liberal, but a bit of both. So, I'm trying to see where & why extremists draw their true/false, good/bad lines.]
This is just wrong. — Harry Hindu
Of course, that evaluation depends on your personal perspective. Right & Wrong are human moralistic categories. The moral authority of Nature is a rhetorical tactic labeled by philosophers as the Naturalistic Fallacy. And it is opposed to the Super-naturalistic Fallacy of monotheism. Nature-in-general is amoral, but Natural Selection seems to have an agenda of some kind. Pros and Cons can argue endlessly about what that the selective criteria might be : local adaptive efficiency or a teleological purpose, etc.
Under this scenario, we wouldn’t expect to see species falling into a nested hierarchy of forms that is recognized by all biologists. — Jerry Coyne - Why Evolution is True
Ironically, that's exactly why anti-evolutionists look to a divine creator to explain such rational (as opposed to random) organization.