zlacker

I don't disagree with your overall point, but I would point out that "happen to share 0.0001% more DNA than any other human" is probably not the best mental model of how to quantify this sort of relationship. Due to combinatorial explosion, these numbers are kind of misleading. It is similar to saying that it is trivial to crack a 1 million bits of entropy password because we already know 99% of the bits. This leaves out that you still have 2^(10000) possible passwords.

Your immediately family shares hundreds of thousands more variable sites in your genome than a 'random' individual. Which is to say there would need to be something like a 2^(100000) population of humans before someone 'random' would be as close to you in terms of variable sites.

I guess my point being "you happen to share 0.0001% more DNA" is just not trivial or a small coincidence that can be waved away with "we are more similar to each other than not". Whether any genetic similarity means that one's biological family deserves one's attention, I have no comment.