William Bateson (8 August 1861 – 8 February 1926) was an English biologist who was the first person to use the term genetics to describe the study of heredity, and the chief populariser of the ideas of Gregor Mendel following their rediscovery in 1900 by Hugo de Vries and Carl Correns.

[3] Taking up embryology, he went to the United States to investigate the development of Balanoglossus, a worm-like hemichordate which led to his interest in vertebrate origins.

His group consisted mostly of women associated with Newnham College, Cambridge, and included both his wife Beatrice, and her sister Florence Durham.

Hilda Blanche Killby, who had finished her studies with the Newnham College Mendelians in 1901, aided Bateson in the replication of Mendel's crosses in peas.

[8] In 1910, Bateson became director of the John Innes Horticultural Institution and moved with his family to Merton Park in Surrey.

During his time at the John Innes Horticultural Institution he became interested in the chromosome theory of heredity and promoted the study of cytology by the appointment of W.C.F.

[18] Bateson's work published before 1900 systematically studied the structural variation displayed by living organisms and the light this might shed on the mechanism of biological evolution,[19] and was strongly influenced by both Charles Darwin's approach to the collection of comprehensive examples, and Francis Galton's quantitative ("biometric") methods.

He saw the persistence of two forms in one population as a challenge to the then current conceptions of the mechanism of heredity, and says "The question may be asked, does the dimorphism of which cases have now been given represent the beginning of a division into two species?"

He was concerned to show that biological variation exists both continuously, for some characters, and discontinuously for others, and coined the terms "meristic" and "substantive" for the two types.

It appears to be caused by the leaking of positional signals across the limb-limb interface, so that the extra limb's polarity is reversed.

But critically, he begins to report a series of breeding experiments, conducted by Edith Saunders, using the alpine brassica Biscutella laevigata in the Cambridge botanic gardens.

Critically, Bateson gave a lecture to the Royal Horticultural Society in July 1899,[28] which was attended by Hugo de Vries, in which he described his investigations into discontinuous variation, his experimental crosses, and the significance of such studies for the understanding of heredity.

[25] Bateson became famous as the outspoken Mendelian antagonist of Walter Raphael Weldon, his former teacher, and of Karl Pearson who led the biometric school of thinking.

Haldane showed that discrete mutations were compatible with gradual evolution, helping to bring about the modern evolutionary synthesis.