Modern biology provides an abundance of empirical evidence that things like populations and ecosystems need diversity to flourish. Inbreeding leads to all sorts of genetic defects; monoculture crops and other simplified environments are more vulnerable to pests, and generally far less able to recover on their own when disturbed.
In a more reflective, interpretive vein closer to ordinary experience, Aristotle already documented the tremendous variety exhibited in nature. Species are not somehow pre-given, but rather to be discerned and understood in terms of specific ways of meeting very general needs.
The fact that there is a superabundance of such ways in nature is one of the most basic observations we can make. Nature as we concretely experience it is much more characterized by this superabundance and diversity than by univocal necessity of the kind we find in mathematics. For Aristotle, an emphasis on this superabundance and diversity goes hand-in-hand with a perspective that looks to purely natural ends and means as more primary in the order of explanation than mechanical metaphors.
This suggests a broader paradigm of intelligibility, reason, and objectivity than the one grounded in mathematics, univocity, and simple necessity. Emotional reasonableness is a real thing that is not at all reducible to formal logic. Similarly, intelligibility, reason, and objectivity in general have a practical reality that should not be understood as requiring a univocal foundation. (See also Bounty of Nature; Equivocal Determination; Multiple Explanations.)
The Postmodern Peripatetic 