ANOTHER BIG CORRECTION: We Were Totally Wrong About That Scott Kelly Space Genes Story. “It turns out we got the story wrong in a big way. In the original story, we reported that 7 percent of Kelly’s genetic code had changed after his stint in space. But that enormous level of genetic change would mean Kelly went to outer space and came back a space alien: All humans share more than 99 percent of our DNA, and we share more than 98 percent of our DNA with chimpanzees, our closest living relatives.”