With the discovery of DNA and the spectacular progress of imaging in the twentieth century, it was assumed that biology had already accomplished its revolution. Quite the opposite, says Catherine Jessus, former director of the CNRS's Institute of Biological Sciences, speaking just before the launch of France's Biology Year, jointly organised by the CNRS and the French Ministry of National Education, Youth and Sport: the frontiers of our knowledge of the living world are constantly being pushed back, posing immense challenges to biologists.