Cyril Dean Darlington, cytogeneticist and evolutionist, was born on 19 December 1903 in Chorley, Lancashire. When he was eight, his family moved to London, where he attended Mercers' School. In 1917 he won a foundation scholarship at St. Paul's School.

Intending to become a farmer in Australia, Darlington attended South Eastern Agricultural College at Wye. He graduated with a B.Sc. in 1923. He applied for an Empire Cotton Corporation scholarship, but was unsuccessful. He accepted a position as a volunteer unpaid worker at the John Innes Horticultural Institution (John Innes). This position became permanent (and paid) in 1924. He was appointed cytologist in 1928, became head of the cytology department in 1937, and from 1939 he also served as director of the John Innes. He was elected a Fellow of the Royal Society in 1941, and received the royal medal in 1946. In 1947 he founded the journal Heredity with geneticist R.A. Fisher. He led the exposure of Soviet atrocities against geneticists led by Trofim Lysenko.

In 1953 Darlington left the John Innes to accept the Sherardian Chair of Botany at Oxford University, and became a keeper of the Oxford Botanic Garden. He created the Genetic Garden, and played an active role in the acquisition of the Nuneham Courtenay Arboretum. He retired from the Sherardian Chair in 1971, but remained at the university writing and publishing. He died in Oxford in 1981.

Darlington's numerous publications include: Recent Advances in Cytology (1932), Chromosome Atlas of Cultivated Plants (1945), The Facts of Life (1953), Genetics and Man (1964), The Evolution of Man and Society (1969), and The Little Universe of Man (1978).