An eyewitness to this century's relentless biological advance and the originator of some of its most important concepts, Ernst Mayr is uniquely qualified to offer a vision of science that places biology firmly at the center, and a vision of biology that restores the primacy of holistic, evolutionary thinking. Both as an overview of the life sciences and as the culmination of a remarkable life in science, This Is Biology will richly reward professionals and general readers alike.