With 6.8 billion people alive today, it's hard to fathom that humans were ever endangered. But 1.2 million years ago, only 18,500 early humans were breeding on the planet. A new method of studying DNA across the whole genome is allowing geneticists to look farther back in time to see the population history of our really ancient ancestors. Click here to read more of this story by Ann Gibbons in ScienceNOW Daily News.
