According to Jerne's biographer Thomas Söderqvist, Jerne did not play the role of a bench scientist, he could not pipette accurately, and he did not enjoy experimental work. Jerne's Nobel Prize was awarded for theories, rather than discoveries. He developed the "natural selection theory of immunology," which was proposed by Paul Ehrlich 50 years earlier, although he was missing the clonal selection element proposed by David Talmage and later by Frank Macfarlane Burnet. James Watson had told Jerne that his theory "stinks."