Attitudes of biologists
Over the years, I have discussed versions of the ideas in this section with many biologists of different kinds. Most are quick to point out at least anecdotal cases in which features of organisms do not seem to have been shaped by natural selection. But if asked about complexity—either in specific examples or in general—the vast majority soon end up trying to give explanations based on natural selection. Those with a historical bent often recognize that the origins of complexity have always been somewhat mysterious in biology, and indeed sometimes state that this has laid the field open to many attacks. But generally my experience has been that the further one goes from those involved with specific molecular or other details of biological systems the more one encounters a fundamental conviction that natural selection must be the ultimate origin of any important feature of biological systems.