Rehabilitation of Karl Popper’s Ideas on Evolutionary Biology and the Nature of Biological Science

Karl Popper’s ideas on evolution in his 1986 Medawar lecture were remarkably close to Charles Darwin’s original distinction between artificial and natural selection, but at odds with the Modern Synthesis in giving an active role to organisms in the process of evolution. His ideas were also compatible with recent work showing the role of the harnessing of stochasticity in enabling this active agency. He also argued against the reduction of biology to chemistry. In this article we show: (1) That these ideas were also compatible with, and flowed from, his work on the Open Society. (2) That organisms are necessarily open systems. (3) That a multi-level analysis of organisms shows that there cannot be causal closure at the micro-level, as proposed by philosophers like Jaegwon Kim. (4) While Popper’s and Darwin’s distinction between active and passive forms of evolution is valid, there is, in the long term, no purely passive form of selection. Organisms also create their environments.