"living" inherently favours those who can breathe - which means those who are already breathing, or from oxygen rich environments where they can be sure of find

"living" inherently favours those who can breathe - which means those who are already breathing, or from oxygen rich environments where they can be sure of finding new O2 molecules quickly. It favours those who can get air from tanks, which are very much old apparatuses. And it favours the kind of lungs that exhale quickly, whatever their other effects.