A year ago, most geneticists had all but dismissed the notion that humans and Neandertals interbred. But with the cataloging of the full Neandertal genome, announced in May, we now know that people of European and Asian descent really have inherited a small percentage of their DNA from a rival species that went extinct about 30,000 years ago.
That’s not all we now know that we didn’t know way back in the first decade of the 21st century. Then, it was still an open question whether NASA’s Kepler mission would be able to fulfill its goal of detecting Earthlike planets orbiting distant stars. Now Kepler has collected evidence for hundreds of extrasolar planets. And another planet search has found hints of an object that appears to orbit the star Gliese 581 at just the right distance to support life.