"The large sample size allows us to see patterns with more clarity than ever before," Novembre said. "If rare variants are like distant stars, this kind of large sample size is like having the Hubble Telescope; it's allowing us to see more than before. We see a ton of rare variation, and these rare variants more often make changes to proteins than not. In that way, this study has important implications for the genetic basis of disease in humans. It's consistent with the idea that many diseases may be partly caused by rare variants."