Life at high altitudes forced ancient Tibetans to undergo the fastest evolution ever seen in humans, according to a new study. The most rapid genetic change showed up in the EPAS1 gene, which helps ...

Editor's Note: We asked several scientists from various fields what they thought were the greatest mysteries today, and then we added a few that were on our minds, too. This article is one of 15 in ...

A flat, rounded shell. A tail that's folded under the body. This is what a crab looks like, and apparently what peak performance might look like — at least according to evolution. A crab-like body ...