Exception, not the rule, but I did warn it was a relatively good empirical formula, not a law of nature :-) I am of the mind that categories such as species ar

Exception, not the rule, but I did warn it was a relatively good empirical formula, not a law of nature :-) I am of the mind that categories such as species are mental constructs to turn the phenomenal world into an approximate model-space so that understanding and action planning can be improved. So for me rather than concepts like "species" being meaningless, they can have meaning (or at least value), but best not to think of them as iron laws. Mostly the point I was hoping to get to in my root response before I diverted myself reading my own text while typing it. It's easier to create iron laws for categorical manipulation than it is to place observations into categories to begin with.