Genetic variability

The BBC reports that human genetic variability is far larger than previously expected. I was expecting this, oddly enough. I’ve read too many reports estimating how closely related species are, and how long ago species diverged based on an estimated mutation rate. This is not my area of expertise, but I had a gut reaction that the world was not that simple, that there had to be a lot more fuzziness in biology than in physics (and there’s a lot of fuzziness when you try to measure things in particle physics). I hope this leads to some new estimates for systematic error in the “mutation clock.”