JLH's pens the best blog entry I have ever read. The only thing I would add is one more link: "Why Some Old Lovers Look Alike."
Yes, it is true: "If your spouse is genetically similar, you're more likely to have a happy marriage, for example. Child abuse rates are lower when similarity is high, and you'll also be more altruistic and willing to sacrifice more for someone who is more genetically like you, research shows."
Like any good survivalist, I just purchased "How to Survive a Robot Uprising." Consider yourselves warned, people!