Julian Huxley’s ‘Epigenetic’ Biology: Origins, Development, and Legacies, 1899-1936

This thesis reconstructs the biological thinking of the British evolutionary, experimental and general biologist Julian Sorell Huxley (1887-1975), the author of the landmark 'Evolution: The Modern Synthesis' (1942). Huxley’s views have had a contested legacy. His work is often equated with the ‘modern synthesis’, celebrated or criticized for combining Mendelian and population genetics with natural selection. Simultaneously, the 1942 book is also prized for embracing a more pluralistic biology that appreciates amongst others the role of development in evolution. This thesis argues that, instead of looking at a single book in isolation, we should examine Huxley’s biological thinking in context, specifically from Huxley’s early Oxford education between roughly 1906 and 1909. Doing so, we stand to better appreciate his later work and ideas. In brief, how and why did Huxley’s biological thinking come to be, and how, at a time when the ‘modern synthesis’ is very much debated, does this allow us to better understand his later work?

I draw upon Huxley’s undergraduate and later essays, reading notes, marginalia, and correspondence as well as upon the published and unpublished work of the remarkable Oxford biologists who shaped Huxley’s thinking in the early twentieth-century. I show that Huxley, along with his tutors, protested against a neo-preformationist view of biology, endorsing instead an epigenetic biology whereby characters were always gradual products of dynamic interactions between internal and external parts. The thesis then demonstrates how the ripples of his Oxford education can be felt in Huxley’s work after 1909, including in his evolutionary writings, experimental work, and in his popular and eugenical work. When we resist the tendency to see Huxley’s 1942 book in isolation from the history of Huxley’s biological thinking as reconstructed from Oxford, we uncover a rich biological epigenetic tradition that stretched back before and extended after 1942.