Darwinian Fitness Day

Yes, today is when Father's get to calculate their Darwinian fitness, which is how many copies of your genes you've passed on to the next generation.  With only one F1 the Phactor has an obvious DF of 0.5.  However it's not actually that simple.  You see the Phactor on average shares a 0.5 genetic heritage with each of his sisters, so on average 0.25 of my genes were passed on to each of their six offspring.  Wow!  Thanks to my sisters my DF has gone up to 2.0.  Now things start to get a lot trickier.  As yet, none of us are grandparents.  But our parents each had siblings with whom they shared a 50% genetic heritage.  And they had children, cousins.  Of course your parents also had cousins who had kids too.  So again a fraction of each of their genes are shared by the Phactor, but now the math is getting to the point where without another cup of coffee no attempt will be made to figure this out.  So there you have it.  Happy Father's Day.  You have a DF of at least 0.5.