What we can learn from the clones that walk among us

Genetically speaking, identical twins ought to be two copies of the same person. Environmentally speaking, if the twins grow up together, they ought to even be influenced by the same things. But if you actually pay attention to identical twins, they aren't identical in personality or interests. How do naturally occurring clones become individual people? That's the subject of a mouse study that Scicurious writes about on her blog. Fascinating stuff.