From BBC News, By Pallab Ghosh- Science correspondent, Edited by - Amal Udawatta, IMAGE SOURCE, PHILIPPE PSAILA/SCIENCE PHOTO LIBRARY Image caption, Remains of a primitive human species known as Homo erectus have been found in Europe dating back to 1.4 million years ago. A big freeze previously unknown to science drove early humans from Europe for 200,000 years, but they adapted and returned, new research shows. Ocean sediments from 1.1 million years ago show temperatures suddenly dropped more than 5C, scientists say. They say our early ancestors couldn't have survived as they didn't have heating or warm clothes. Until now, the consensus had been that humans had existed in Europe continuously for 1.5 million years. Ancient humans' stone tools found in Kenya Ancient human remains found in County Armagh Ancient humans survived longer than we thought Evidence for the big freeze is found in sediments in the seabed off the coast of Lisbon, Portugal. Layers are deposited eac