Julian Lewis, English biologist and academic (born 1946)

Julian Hart Lewis FRS was an English developmental biologist and researcher whose work shed light on the nature of cellular timing mechanisms and their role in animal development. He showed that the Notch ligand controls the timing of nerve cell differentiation and the synchronised cycling of neighbouring cell activity. He modelled the cellular oscillatory circuit that determines the segmentation of the developing body, and clarified the importance of delay kinetics in setting the frequency of those oscillations.