I rename duplicates. I'm not organzed enough to figure family trees yet--I'm only on my first and second games still. Some of the standard names I just didn't like, so I love this feature. "Tuna" was one of the ones I couldn't deal with, but "City" was okay for some reason. I'm thinking of starting a new game just to play with the names more--I like the idea of giving each generation a different theme.