It has been claimed that human males have a successful reproduction rate of about 40%, whereas females have 80%. This leads to the claim that we have about twice as many unique female ancestors as male. My understanding is that this claim is based on looking at the ratio of the number of generations to our most recent female common ancestor and our most recent male one.
Do we have similar data for other species? I'm especially interested in whether there are species where the number of unique male ancestors is greater than the number of female ones. Is a role reversal, like in seahorses, is sufficient to invert the ratio? Does the ratio invert for bees and ants (species where I understand, each female mates with more than one male)?