nubben

I am sorry for the bad question. What i am asking is when did biological experts first understand, when oxygen came after life. Eg when did the scietific communtiy come to a conclusion that life predated oxygen. I've just started to get into scientific questions so im not that good a writing the questions to get to the point of my thoughts.

I was wondering when scientist figured out when oxygen took a place in evolution. When did they know that oxygen was a byproduct before it was essential for life. At what time did they figure out that oxygen came later?