All Human Beings Are Descendants of Adam

No, not really. There was a bottleneck, but that isn't why ME existed.That's just inevitable. Humans are one species, everyone has a mother, and no-one has more than one mother. Given these facts, one can prove the existence of ME from one's armchair.People often get confused about this. The fact that ME existed was not news. It was inevitable. The date and location at which she existed was news.If I was one of those scientists I'd have gotten downright testy about that.

Common sense confirms the fact that we are all descendants of at least two human beings. As I said, it was not big news that ME existed. She had to.Common sense also suggests that this is probably true of more than two human beings.Genetic analysis, IIRC, suggests that "Y-nuclear Adam" and "mitochondrial Eve" didn't live at the same time; which would make reconciling the facts with the Bible kinda tricky.Edited by Dr Adequate, : No reason given.

Mitochondrial Eve is by definition our most recent common ancestor in the female line. There can only be one of those.This is not to say that you'd have noticed anything special about her at the time. She's unique because she's been carefully defined so as to be unique.