Sir Julian Sorell Huxley FRS (22 June 1887 – 14 February 1975) was a British evolutionary biologist, philosopher and eugenicist. He was secretary of the Zoological Society of London (1935–1942). Huxley was also a prominent member of the British Eugenics Society and was its president from 1959–1962. He was grandson of Thomas Huxley, also known as "Darwin's Bulldog".
Huxley together with his fellow biologist August Weismann maintained that natural selection was the main driving force of evolution going against saltationism. To Huxley, evolution occurs through the accumulation of slight modifications over long periods of time (gradualism) causing speciation to happen slowly.
- Baker, J. R. (1976). "Julian Sorell Huxley. 22 June 1887 – 14 February 1975". Biographical Memoirs of Fellows of the Royal Society 22: 206–226.