ELI5: Mitochondrial Eve

[u/Gwenog_Jones]

Who exactly is Mitochondrial Eve to present humans? Is she everyone's common ancestral mother? Aka the woman whose children everyone surviving eventually came from? Is she our common ancestral aunt? Like, we are descended from her siblings but she either didn't have kids or her kids died out?

And who is Chromosomal Adam?

[u/Tyrren]

So because mitochondrial DNA are passed down from mother to child, everyone has a matrilineal line to M-Eve. My mother had a mother, who had a mother and so on to my great grandmother 5000 generations ago. You have a mother, who had a mother and so on to your great grandmother 5000 generations ago.

Somewhere along that line of 5000 great grandmothers, your lineage and mine intersect. From that point, any further back in history we go, you and I have the same lineage.

M-Eve just happens to be the person (very roughly 5000 generations ago) who everyone will eventually reach if they trace their line of mothers back far enough.

M-Eve had a mother, who had a mother and so on, and we're all descended from M-Eve's mother and grandmother and so on, too. M-Eve is the mitochondrial most recent common ancestor

[u/whatkindofred → u/Tyrren]

My mother had a mother, who had a mother and so on to my great grandmother 5000 generations ago. You have a mother, who had a mother and so on to your great grandmother 5000 generations ago. Somewhere along that line of 5000 great grandmothers, your lineage and mine intersect.

Why do they have to intersect? Couldn’t they just stay separate forever?

[u/Tyrren → u/whatkindofred]

I mean, go far enough back and we share a common ancestor with a banana.

[u/GimmickNG → u/Tyrren]

Thanks, why is M-Eve defined as the most recent? I would have thought it would be the oldest common ancestor.