According to Jerne's biographer Thomas Söderqvist, Jerne was not a bench scientist, could not pipette accurately, and did not enjoy experimental work. His Nobel Prize was awarded for theories, rather than discoveries. Jerne developed the "natural selection theory of immunology", proposed by Paul Ehrlich 50 years earlier, although he was missing the clonal selection element proposed by David Talmage and then by Frank Macfarlane Burnet. It was met by skepticism among his colleagues at first, James Watson for example told Jerne bluntly that his theory "stinks".