Steven Pinker -- How the Mind Works - Hampshire High Italian ...

166 J HOW THE MIND WORKScomplex organs are a product of drift or a by-product of some other adaptation.Everyone acknowledges that the redness of blood was not selectedfor itself but is a by-product of selection for a molecule that carries oxygen,which just happens to be red. That does not imply that the lability ofthe eye to see could easily be a by-product of selection for something else.There also are no benighted fools who fail to realize that animals carrybaggage from their evolutionary ancestors. Readers young enough tohave had sex education or old enough to be reading articles about theprostate may have noticed that the seminal ducts in men do pot leaddirectly from the testicles to the penis but snake up into the body andpass over the ureter before coming back down. That is because the testesof our reptilian ancestors were inside their bodies. The bodies of mammalsare too hot for the production of sperm, so the testes graduallydescended into a scrotum. Like a gardener who snags a hose around atree, natural selection did not have the foresight to plan the shortestroute. Again, that does not mean that the entire eye could very well beuseless phylogenetic baggage.Similarly, because adaptationists believe that the laws of physics arenot enough to explain the design of animals, they are also imagined to beprohibited from ever appealing to the laws of physics to explain anything.A Darwin critic once defiantly asked me, "Why has no animal evolvedthe ability to disappear and instantly reappear elsewhere, or to turn intoKing Kong at will (great for frightening predators)?" I think it is fair to saythat "not being able to turn into King Kong at will" and "being able tosee" call for different kinds of explanations.Another accusation is that natural selection is a sterile exercise inafter-the-fact storytelling. But if that were true, the history of biologywould be a quagmire of effete speculation, with progress having to waitfor today's enlightened anti-adaptationists. Quite the opposite has happened.Mayr, the author of a definitive history of biology, wrote,The adaptationist question, "What is the function of a given structure ororgan?" has been for centuries the basis of every advance in physiology. Ifit had not been for the adaptationist program, we probably would still notyet know the functions of thymus, spleen, pituitary, and pineal. Harvey'squestion "Why are there valves in the veins?" was a major stepping stonein his discovery of the circulation of blood.From the shape of an organism's body to the shape of its, protein