Human Origins: Let's Talk Mitochondrial Eve

I'll let others go into details but this is wrong: (bolding mine)There is no suggestion that this is a first woman. It is a last woman. The last woman for whom there are current female descendants.Let me see if I can explain how this can happen.Let's go to a small village some 100's of years ago. There are 100 males in it, each with a different surname. Smith, Jones, Alson, etc. etc. The totally firm rule is that sons get their dad's last name and that women change theirs on marriage. The village stays small because they have very small families (or they move away or whatever)They have children; some have both sons and daughters, some have sons and some have only daughters.If in one generation all the Jones's happen to have only daughters there will never be any Jones's after that. You can, I think, calculate how long it will take until you have only one surname left.However, all of the original males may well have descendants in the population through the female lines.The mitochondrial DNA is like the surname but for women and it is really a firm rule. If the original population is small enough you will, I think, end up with only one of those with surviving direct female descendants.That does NOT say that the other women don't have (tense is funny here) surveying descendants. But somewhere in the line there was a generation of only males.Edited by NosyNed, : to connect this to the females and correct spelling of surname

I don't know the right answer for sure but I think this has to do with population genetics as I hinted at in my earlier post. I believe it is possible to do the calculations and determine that there has to be a small enough population at some point for only one DNA line to reach to today. I'm sure someone will clear that up.It is by a comparison of the differences in the DNA that the likely location of the "eve" is determined. It is part of learning about our past.