Let's say that we find a plant in the Amazon that will cure AIDS, but to get it we would cause irreparable harm to the plant. Most people would side with humanity in this case. We have a tendency as a species to recognize our specialness over against all other life. We allow experimentation on animals, etc.
That is a paraphrase, though as close to remembering what he said verbatim as I can. The problem with that, the absolutely glaring flaw, is that the kind of species chauvinism he is speaking of fits quite neatly into the evolutionary perspective, which imagines the perpetuation of the species as the driving force behind animal behavior. It does not separate us from animals. It reveals our animal brutality, the willingness to disregard the rights of other living creatures in order to perpetuate our own species. I think it would reveal the particularity of humanity more to point out the times when we refuse to press the rights of our own species against the rights of other species.
All of that, of course, is said without comment on the actual ethics of killing plants to cure AIDS.