Arsenic Before Oxygen?
· β 211 words science · βοΈ Peter Hiltz
So we know that life has existed on Earth for billions of years (think bacteria, not dinosaurs) but we also know that bacterial life existed for 1.5 billion years before there was free oxygen present. Life as we generally know it requires oxygen serve as a vehicle for electrons gained and lost through various metabolic processes. How did it all work pre-oxygen?
There have been various theories posited, including life processes using hydrogen or sulfur or iron.