This also was utterly fascinating:
"The first big, basic difference has to do with what I consider to be the most underappreciated fact about gender. Consider this question: What percent of our ancestors were women?
It’s not a trick question, and it’s not 50%. True, about half the people who ever lived were women, but that’s not the question. We’re asking about all the people who ever lived who have a descendant living today. Or, put another way, yes, every baby has both a mother and a father, but some of those parents had multiple children.
Recent research using DNA analysis answered this question about two years ago. Today’s human population is descended from twice as many women as men."
I had no idea... they must have tested mitochondrial dna or something?
A good way to visualize this is to imagine a family tree going back for many, many generations. You'd find that certain males were your ancestor "more than once", i.e. you might find the same man was your ancestor on both your mother and father's side.
Of course, females can also be your ancestor "more than once"; it's just that, as a matter of fact, more men have this property. This is due to the fact that some men have dozens of children, by several different women.
Mitochondrial DNA would give you female diversity and the Y chromosome would give you male diversity.
As to why the discrepancy? Male babies have a lower survival rate. Among the Amazonian Yanomami 40% of the men are murdered or killed in combat. That would lower your odds of being an ancestor.
No: there are less total fathers than mothers, because more people have the same father than the same mother. People who haven't lived long enough to reproduce have no impact on that figure.
There are extreme cases for both genders. While my paternal grandmother had seventeen kids, the comparatively extreme male case probably had well over a hundred. You can only give birth so many times, so the upper bound for women is lower.
> People who haven't lived long enough to reproduce have no impact on that figure.
They impact it indirectly. Say you have a tribe with 12 men and 12 women. 11 men die (before they can reproduce.) Then the next generation has 1 father and 12 mothers. One could say that the men's deaths caused more people to have the same father. So having a lot of men die before reproducing increases the strength of the effect, under the assumption that women will usually reproduce regardless.
Obviously the root cause is that men can bear more offspring, that much is obvious.
It’s not a trick question, and it’s not 50%. True, about half the people who ever lived were women, but that’s not the question. We’re asking about all the people who ever lived who have a descendant living today. Or, put another way, yes, every baby has both a mother and a father, but some of those parents had multiple children.
Recent research using DNA analysis answered this question about two years ago. Today’s human population is descended from twice as many women as men."
I had no idea... they must have tested mitochondrial dna or something?