Fire and Knowledge

A common claim, stated often enough to merit the label of “urban legend,” holds that no such transitional forms exist and that the paleontologists, dogmatically committed to evolution, have either withheld this information from the public or have claimed that the fossil record is too imperfect to preserve the intermediates that must once have existed.

In fact, although the fossil record is indeed spotty (a problem with nearly all historical documents, after all), the assiduous work of paleontologists have revealed numerous elegant examples of sequences of intermediary forms (not just single “in between” specimens) joining ancestors in proper temporal order to very different descendants—as in the evolution of whales from terrestrial mammalian ancestors through several intermediate stages, including Ambulocetus (literally, the walking whale), the evolution of birds from small running dinosaurs, of mammals from reptilian ancestors, and a threefold increase in brain size during the last 4 million years of human evolution.

–Stephen Jay Gould in Carl Zimmer, Evolution: The Triumph of an Idea, p. x