Karl Popper (1902-1994), one of the foremost philosophers of the twentieth century

The philosopher of science, Karl Popper, who did so much to formalise the scientific method as hypothesis testing and falsification, notoriously suggested that evolution was not a scientific theory because it was not testable. “Darwinism is not a testable scientific theory, but a metaphysical research program” (Unended Quest, 1976). However, he later retracted this view and provided a cogent and convincing argument for how evolutionary theory is a scientific one.

The two platforms of science for Popper were the formulation of bold, challenging hypotheses and testability. The former has played a major part in human evolutionary studies, while the latter has posed challenges as it has for all historical sciences.