While I take offense at the insinuation that conservatives in general would want to segregate, I'll ignore that for the sake of discussion. I think the turtle thing was just to summarize, in a rather silly way, how his findings showed that, generally in America, diversity led to people keeping to themselves. The point of the article wasn't to explain that this is how all countries work, just how the majority of America seems to work. I, myself, would be rather interested in seeing how this goes in Canada or Europe. I don't think he believes that we've failed in creating diverse communities, just that we need to modify our methods a bit. Scientists have also found that babies are racist, so there is something to be said as far as this being a normal thing, if not entirely desirable.
I didn't mean to offend, but I think it is fair to state that the social right in most countries gravitate towards ideas about ethnic purity and cultural homogeneity. The thing that annoyed me the most about Putnam is that he seems to entertain the idea that diversity is "bad". IMO he should be using these findings to suggest educational programs teach people about tolerance. Just because humans are evolutionarily programmed to use phenotypes as cues for social kinship, it doesn't mean that we can't create a world that accepts and embraces diversity. Our evolutionary history has left us with a lot of genetic baggage that we must overcome by embracing inclusive cultural attitudes and ingraining the notion that we are one species; not several divided races and ethnicities.