Question: If there was never oxygen, would we be alive? Or would there be just no beginning? Please answer me!

Pete Etchells answered on 1 May 2012:

That’s a really interesting question. The basic answer is that we can’t survive without oxygen, so human life wouldn’t have been able to start without it. However, there are forms of life that don’t need oxygen to survive – for example, anaerobic bacteria. It’s unlikely that higher forms of life could have evolved from these, as we don’t really see any examples now. But it wouldn’t be out of the question!