The South African War of 1899–1902 constituted a major political rupture. In the postwar period, science and technology consolidated the embryonic state and legitimated white authority – and racial segregation – by valorising rationality, order and progress. Members of scientific associations helped to build the university system which expanded rapidly after the First World War. The confluence of scientific and industrial expertise in Johannesburg was signalled by the establishment of a South African Institute for Medical Research in 1912. The national Department of Agriculture was a key employer of applied scientists, and veterinary researchers at Onderstepoort tackled a range of animal diseases. Innovative individuals such as Junod, Merensky and Marais advanced entomology, geology and zoology. Jan Smuts and J.H. Hofmeyr were committed to active participation in the emergent Commonwealth, viewing science as a means to transcend differences between English- and Afrikaans-speakers. In the 1920s and 30s both became strong advocates of the ‘South Africanisation’ of science and of research in the southern hemispheres. These included new theories of continental drift developed by Alexander du Toit, as well as remarkable paleontological discoveries indicating South Africa’s importance in the evolution of humankind.