Karl Popper's lecture A New Interpretation of Darwinism given at the Royal Society London in 1986 is here printed for the first time in the original. In it, Popper denies the creative power of blind chance and natural selection. Instead of these two Darwinian dogmas he establishes knowledge and activity of all organisms as the creative driving forces of evolution. Hans-Joachim Niemann unearths biographical details about the year 1936 when Popper's biological thoughts were inspired by a meeting with some scientists of the avant-garde of molecular biology. He then focusses on the year 1986 when Popper, in several lectures, summarized the results of his life-long biological thinking. After that Niemann discusses Popper's philosophy of biology in the light of new results of molecular biology that apparently supports his endeavour to overcome some gloomy aspects of Darwinism. How the new creative forces knowledge and activity came into existence is still a secret and a worthwhile research programme.