Things you wish you could say

Even if everyone is descended from one particular woman, it may not tell much about how many other people were alive at the time.

For example:
I am descended from my great grandmother. I have a cousin who is descended from the same great grandmother. But we each have 3 other great grandmothers who were living about the same time (plus 4 great grandfathers). The one great-grandma that I share with my cousin is our common ancestor but she is not the only ancestor of either of us.
No, but my understanding is that mitochondrial dna is passed only from a mother to her daughters. If there is a single male ancestor between you will not show up as her descendant.
 
No, but my understanding is that mitochondrial dna is passed only from a mother to her daughters. If there is a single male ancestor between you will not show up as her descendant.
True enough. I was mostly trying to make an example of how people can be descended from "one woman" without being descended ONLY from that woman. It happens that I do have a cousin who shares a great-grandmother with me through a line of just women.

My understanding is, if you follow the mitochondrial dna back far enough, you do find some point at which it all traces back to a single woman. I've also read that it can trace back to a different woman depending on when and how it is being checked (If the woman had two daughters, and the chain of female-only transmission breaks for all descendants of one daughter, then the other daughter would now be most recent female ancestor of everyone. Or if people are found who are not descended from the one woman, they and she can trace back to a different single female ancestor, so the label shifts to that longer-ago woman instead.)
 
It's fascinating. The male line (autosomal? I can't remember) changes faster so it's easier to track over time.
Autosomal would not be the right word. Autosomes are all the chromosomes that are not sex chromosomes. In chickens, that is everything except ZW. In humans, everything that is not XY.

I assume you are referring to the human Y chromosome. There probably is another word for it, but I don't know what it is.
 

New posts New threads Active threads

Back
Top Bottom