Lewis Wolpert. 19 October 1929—28 January 2021

Abstract

Lewis Wolpert was a theoretical biologist who, through his background as an engineer, introduced insightful ways of thinking about embryonic development. As a charismatic speaker and writer, he had a parallel career as a public spokesman and advocate for science. Wolpert's most significant scientific contribution was the concept of positional information, which provides a model for the way in which cellular activities are controlled in space and time, in defining the body plan of the embryo and in generating organized arrays of differentiated cells. Wolpert studied sea urchin development, and is known for saying ‘gastrulation is truly the most important time in your life’. He illustrated the problem of pattern regulation by analogy to the French flag, which has the same pattern of coloured stripes irrespective of size. Wolpert applied the concept of positional information to regeneration in Hydra and to pattern formation in the developing chick limb. He was involved in the discovery that retinoic acid can change positional values in the limb, and when developmental genes were uncovered his work provided the basis for understanding their functions. He thought deeply about development, contributing to discussions on handedness and evolution. Wolpert edited journals and wrote an influential textbook on developmental biology. In his parallel career, Wolpert was a highly visible public intellectual, speaking up for science as a broadcaster, author and journalist. One of his greatest contributions to the public understanding of science was his book about depression, Malignant sadness , which brought scientific understanding, solace and hope to many.