An evolutionary biologist who presented an entirely new synthesis of evolution (The Major Transitions in Evolution, with J. Maynard Smith), ranging from the origin of replicators to the origin of the human language faculty. The reviewer of Evolution regarded it as the most important book on evolution since 1930. His "stochastic corrector" is a seminal approach to the transition from independently replicating units to a higher-level unit of evolution, which resolved a main paradox in the origin of life. He was the first to propose an explicit experimental protocol for the in vitro selection of RNA aptamers and ribozymes. He also presented one of the main, testable theories for the origin of the genetic code ("coding coenzyme handles") he is the main contributor in the world to the classification and evolution of replicators, from the chemical to the cultural. His extremely fruitful ideas are of paramount importance to the whole field of evolution.