J.B.S. Haldane

John Burdon Sanderson Haldane (5 November 1892 – 1 December 1964), nicknamed "Jack" or "JBS", was a British-born scientist and polymath, and a foundational figure in the modern synthesis of evolutionary biology. He worked in the fields of physiology, genetics, evolutionary biology, and mathematics. With innovative use of statistics in biology, he was one of the founders of neo-Darwinism. Largely self-taught in biology, he held professorships at the University of Cambridge, the Royal Institution, and University College London. Renouncing his British citizenship, he became an Indian citizen in 1961 and worked at the Indian Statistical Institute until his death in 1964.

Haldane's article on abiogenesis in 1929 introduced the "primordial soup theory", which became the foundation for the concept of the chemical origin of life. He established human gene maps for haemophilia and colour blindness on the X chromosome, and codified Haldane's rule on sterility in the heterogametic sex of hybrids in species. He correctly proposed that sickle-cell disease confers some immunity to malaria. He was the first to suggest the central idea of in vitro fertilisation, as well as concepts such as hydrogen economy, cis and trans-acting regulation, coupling reaction, molecular repulsion, the darwin (as a unit of evolution), and organismal cloning.

In 1957, Haldane articulated Haldane's dilemma, a limit on the speed of beneficial evolution, an idea that is still debated today. He is also remembered for his work in human biology, having coined "clone", "cloning", and "ectogenesis". With his sister, Naomi Mitchison, Haldane was the first to demonstrate genetic linkage in mammals. Subsequent works established a unification of Mendelian genetics and Darwinian evolution by natural selection whilst laying the groundwork for modern synthesis, and helped to create population genetics.