While we may think of ourselves as sharing 100% of our genes with whole siblings, that is true only of identical twins. I was just corresponding with someone about cousin marriages and found this chart. This shows 50% shared "blood??" with siblings, meaning I'd probably have 25% shared "blood" with my half-siblings...

http://www.ziemiecki.com/cousins.html

I always remember seeing pictures of the LOVING family which was the case that got the laws prohibiting interracial marriages declared unconstitutional. They had 4 children at the time and one "looked" to be 100% white (blonde), two were in the middle and one was a bit darker.

I had a co-worker who had one parent who was Portuguese-American and one who was likely Heinz 57 American. My co-worker was blonde, blue-eyed, she had a redhead sister and a brother who had been mistaken for Hawaiian.

Obviously a real shuffling of the genes/chromosomes with each birth.

tootncmon