Thomas Henry Huxley (1825 - 1895) was a British biologist who earned the nickname 'Darwin's Bulldog' by passionately supporting Darwin's ideas. He particularly defended the evolutionary view against religious attack, and Darwin himself referred to Huxley as 'my general agent'.
In 1863 Huxley became the first to explicitly state that humans did not occupy a unique biological position in nature. He was also the first to try to explain the existence of altruism by suggesting that the group, and not the individual, is the unit of selection (see group selection and levels of organization).
In 1881 Huxley became President of the Royal Society. His descendents were also intellectually distinguished, including his son Leonard, and his grandsons Julian, Aldous and Andrew.
Julian Huxley (1887 - 1975) contributed to the founding of the modern synthesis, introducing the concepts of Fisher, Haldane and Wright to many biologists.
This photograph of Julian Huxley was taken in 1918.