I recently asked more than seventy eminent researchers if they would have done I their work differently if they had thought Darwin's theory was wrong. The responses were all the same: no. I also examined the outstanding biodiscoveries of the past century: the discovery of the double helix; the characterization of the ribosome: the mapping of genomes; research on medications and drug reactions: improvements in food production and sanitation; the development of new surgeries; and others. I even queried biologists working in areas where one would expect the Darwinian paradigm to have most benefited research, such as the emergence of resistance to antibiotics and pesticides. Here, as elsewhere, I found that Darwin's theory had provided no discernible guidance, but was brought in, after the breakthroughs, as an interesting narrative gloss.