A more subtle issue concerns the mechanisms of biological evolution; and here our modern scientific understanding took a longer time to develop. Though the basic idea — descent with modification, combined with natural selection — was set forth with eminent clarity by Darwin already in his 1859 book, the precise mechanisms underlying Darwinian evolution did not become fully elucidated until the development of genetics and molecular biology in the first half of the twentieth century. Nowadays we have a good understanding of the overall process: errors in copying DNA during reproduction cause mutations; some of these mutations either increase or decrease the organism’s success at survival and reproduction; natural selection acts to increase the frequency in the gene pool of those mutations that increase the organism’s reproductive success; as a result, over time, species develop adaptations to ecological niches; old species die out and new species arise. This general picture is nowadays established beyond any reasonable doubt, not only by paleontology but also by laboratory experiments.
The intent behind Sokal’s essay here is something I respect, but a lot of pompous blah about taking science seriously is close to laughable when it sifts through the Darwin cliches. The critics of darwninism have pointed out the problems over and over, so it is essential to have one’s head above water here and not peddle boilerplate.