OK, just trying to settle an argument between two non-science people -
how long would something like menstruation take to evolve? The argument
that I have been presented with is that woman began menstruating (rather
then doing what other critters do (which I can't remember the scientific
term for but is basically go into heat)) after people began living in
more fixed shelters between - let's say for arguement sake between
5000-15000 years ago. Would this be enough time for this to evolve?
Thanks for your time,