When it gets warmer vegetation and animal life adapt and change. Different populations move in from warmer climes to former colder climes. One widely held assumption is that it gets colder as the elevation gets higher so that as the climate gets warmer life that has adapted to a warmer environment will go higher pushing the colder based life forms out. In a paper published January 20th in the journal Science, a University of California researcher and his co-authors challenge a widely held assumption that plants will move uphill in response to warmer temperatures. Between 1930 and 2000, instead of colonizing higher elevations to maintain a constant temperature, many California plant species instead moved downhill an average of 260 feet.