The year 2011 saw scientific research that stretched from the farthest reaches of the universe to the deepest mysteries of the cell. Following a yearly tradition, Science's editors and news staff have selected one scientific Breakthrough of the Year and nine runners-up -- and have also highlighted some areas to watch for 2012.
This year's runners-up for Breakthrough of the Year highlight exciting developments in medicine, the history of the universe, human ancestry, and more.