LEONARDO'S MOUNTAIN OF CLAMS AND THE DIET OF WORMS

In the latest selection from this self-described “essay-machine,” Gould gathers together sundry Natural History columns, mingling natural history knowhow with his characteristic humanist outlook. Gould (Zoology & Geology/Harvard, Questioning the Millennium, 1997, etc.) takes his main cue here less from great scientists’ successes than from their all-too-human blunders. Opening with a masterful appreciation of da Vinci’s remarkable observations about erosion and fossilized clams—and their lesser-known context of his entirely medieval world-view—Gould displays a deep appreciation not only for the natural world but also for the mind’s attempts to understand it, even at the risk of error. “Nothing can be quite so informative and illuminating as a truly juicy error,— he observes in his discussion of the unsung 18th-century naturalist Mendes da Costa’s attempted application of the hierarchical Linnean nomenclature to rocks. Equally juicy errors addressed elsewhere include astronomer Percival Lowell’s “canals” of Mars and the way Lowell’s ideas about extraterrestrial life resurfaced in the 1996 debate over bacterial evidence in a Martian meteorite; Russian Vladimir Kovalevsky’s groundbreaking classification of the horse’s ancestry along Darwinian evolutionary lines; and Victorian physiologist Walter H. Gaskell’s nuttily wrong “inversion theory” about vertebrates and invertebrates, which actually enjoys a kind of resonance on the genetic level. Some errors deserve only castigation (or correction), such as the loss of the dodo both as a species and a scientific specimen (only fragments remain in museums). Gould also assays topics ranging from the coexistence of hominid species in human evolution to a gruesome root-headed parasite. However out-of-left- field the subject, he still manages to charm us with characteristically energetic, down-to-earth lucidity. Gently iconoclastic, always illuminating essays from the science writer whose prose can bring to life not only theories but even the fossils themselves. (30 b&w illustrations)