English journalist Hitching (An Atlas of the Unexplained) has a fine time airing for the general public the not-so-quiet infighting among scholars of evolution. At the heart of the matter is not whether evolution took place, but whether Darwin's explanation and the latter-day refinements of it--the ""modern synthesis,"" or ""neo-Darwinism""--are correct. Darwin described natural selection as a force in the environment that slowly shaped the development of species by virtue of the reproductive advantage certain individuals enjoyed: the survival value of a warm coat or longer legs. In time, advantageous traits accumulated and new species formed. The 20th Century seized upon the gene as the bearer of individual traits, and random mutations of genes as the way new or better traits were produced. Disputants argue, however, that evolution is not slow and gradual, that organs don't go through intermediate stages (a bird wing is a bird wing, never a half-feathered reptilian appendage), that strata show sudden and dramatic changes in fossils. To describe evolutionary history, Stephen Gould and others have championed ""punctuated equilibrium"": long periods of species stasis interrupted by sudden appearances of new forms. Catastrophism is pondered. Vague laws of morphology are hinted. The notions of negative entropy of Ilya Prigogine are bandied about. Hitching delights in presenting these alternative views. He is hard on Darwin, invoking the ghosts of plagiarism (or at least unattributed influences), as well as depicting him as sick and neurotic. He is even harder on today's creation scientists, though more polite in putting them down. What's missing is a more objective perspective. There are no statements from molecular biologists who argue that genetic change can occur rapidly: the gene-splitting that makes headlines today is simply repeating what nature herself has done. Other theories, like neoteny, are only hazily discussed. Still, this is a lively reading on a subject of particular importance today. It should stir quite a brew.