gim

I figured, and it seems to be right, that on average, siblings will have 50% of their DNA in common. The words "on average" are important here, because they may share more or less that 50% of their DNA. What I can't figure out is this. Say I have two siblings. If I look at their combined DNA, how much of it will be the same as mine (on average)? Obviously more than 50%, but less than 100%. This is a statistical thing, and I would like to be shown how to work it out. Thanks, Greg.