John Burdon Sanderson Haldane was a British geneticist, biometrician, physiologist, and popularizer of science who opened new paths of research in population genetics and evolution.
Son of the noted physiologist John Scott Haldane, he began studying science as assistant to his father at the age of eight and later received formal education in the classics at Eton College and at New College, Oxford (M.A., 1914). After World War I he served as a fellow of New College and then taught at the University of Cambridge (1922–32), the University of California, Berkeley (1932), and the University of London (1933–57).
In the 1930s Haldane became a Marxist. He joined the British Communist Party and assumed editorship of the party’s London paper, the Daily Worker. Later, he became disillusioned with the official party line and with the rise of the controversial Soviet biologist Trofim D. Lysenko. In 1957 Haldane moved to India, where he took citizenship and headed the government Genetics and Biometry Laboratory in Orissa.
Haldane, R.A. Fisher, and Sewall Wright, in separate mathematical arguments based on analyses of mutation rates, population size, patterns of reproduction, and other factors, related Darwinian evolutionary theory and Gregor Mendel’s concepts of heredity. Haldane also contributed to the theory of enzyme action and to studies in human physiology. He possessed a combination of analytic powers, literary abilities, a wide range of knowledge, and a force of personality that produced numerous discoveries in several scientific fields and proved stimulating to an entire generation of research workers.
Darwin and Wallace announced their theories of evolution by natural selection in 1858, and the following year Darwin published his majestic book "The Origin of Species". By 1932, when British scientist J.B.S. Haldane wrote "The Causes of Evolution", evolution was firmly established as a scientific fact (although some were - and still are - willing to keep arguing the point). The mechanism of natural selection had, however, been through a harder slog towards acceptance.
Darwin wrote that evolution by natural selection depends on three things: variation, inheritance, and hyperfecundity (a fancy way of saying "plenty of offspring to select among"). In his writings he demonstrated in countless ways how these three factors ultimately lead to the evolution of new species. Unfortunately he was never able to point to good physical explanations for the sources of variation, or to explore exactly how the mechanisms - environmental, social, sexual, etc - that create selection pressure actually work. As scientists peered more closely at the theory of natural selection, they struggled to explain some of the more counter-intuitive elements, such as the persistence of non-adaptive traits.
Darwin died in 1882, and for a few decades thereafter the theory of natural selection lost some of its sheen. The fire was rekindled in the first decades of the 20th century by the discovery of genetics and the mechanisms by which genes are transmitted through chromosomes. Then in the 1920s and 1930s, scientists - Haldane prominent among them - applied statistical techniques to the distribution of genes in populations, and showed how breeding populations generate the variation that fuels natural selection.
It's sad to think that a book as important in its time as "The Causes of Evolution" should be almost unreadable now. Unless you're a professional botanist or geneticist, you won't know which observations are still technically correct, and it's hard not to apply the context of later discoveries like DNA, RNA, and the whole apparatus of molecular biochemistry. But you can get a sense of what it is like to be a scientist struggling at the edge of knowledge.