You seem to be tripped up on the difference between causality and necessary conditions, and also on analogies, generally. As but one quibble: you can't admit o

You seem to be tripped up on the difference between causality and necessary conditions, and also on analogies, generally. As but one quibble: you can't admit oxygenation to be necessary for multicellular life but not dinosaurs. Unless there are some single-celled dinosaurs, which I am now liable to dream about, thankyouverymuch.