I'm in the 'we're unique' camp. The contingencies that created us are improbable and overwhelming and would be astronomically (cough) unlikely to occur again, and a number of them seem to be indispensible, as well as very unlikely. I, for one, welcome our magnificent existence. We are the universe; it's eyes and mind. We're IT. I like the note, 'our biosphere has never collapsed.' You mean it hasn't collapsed yet.