Sudden Origins: Fossils, Genes and the Emergence of Species Book

Where did all the astonishing variations on the theme of life come from? Darwin persuaded us that God did not create them--earwigs and elephants, ferns and falcons--all at once. He thought one life form gradually evolved into another. But ever since, some have argued that the fossil record makes it look as if some species did appear all of a sudden. The intermediate forms just aren't there in the rocks. Look as hard as you like, the missing links stay missing. Jeffrey Schwartz thinks he knows why. The answer, he says, lies in the recently discovered "homeobox" genes. These are stretches of DNA code which show up across an amazing range of species. Since they regulate the exact way the expanding ball of cells in an embryo grows up, changes in these genes can alter a creature's whole body plan. Schwartz, an expert on human evolution, thinks they are the key to the jumps in the fossil record. By provoking big changes, they can turn one species into another. He explains how in great detail--too much of it for anyone wanting a quick read. But the end result is a satisfying synthesis of the latest in molecular biology with evolutionary theory. Nicely explained too, though not as earth-shattering as the book makes out. Evolution is still driven by changes in the genes: it is just that some genes are more important than others. --Jon TurneyRead More