ok, umm, what?

- it's well known that oxygen levels rose dramatically around 2 billion years ago as a result of life producing it as a waste product. the free oxygen in the atmosphere was mostly produced through this process.
- in fact, the oxygen levels became so high that they poisoned the existing life, causing a mass extinction.
- that clearly demonstrates that oxygen is not "required for life". what is a plant's reaction to oxygen?
- oxygen-metabolizing life forms then evolved from oxygen-emitting life forms as a response to all the poisonous oxygen in the atmosphere.

after reading this a few times, my best guess is that the scientist who did the study is specialized to the cambrian and was simply never taught about the oxygenation event.

http://www.astrobio.net/pressrelease/5758/oxygen-not-the-cause-of-the-cambrian-explosion

most working scientists are nothing approaching a polymath. they know what they're taught, which is very narrow.

spare time is spent watching dumb sitcoms like every other idiot.