The New York Times, November 6, 2007
About half a billion years ago, our ancestors were slender, jawless, fishlike creatures. Their backs were stiffened by a rod of cartilage, along which grew bony prongs. That smattering of bone was the forerunner of our vertebrae, and it gave us and all the other descendants of those ancient animals our name: the vertebrates. Vertebrates have evolved into tens of thousands of species dominating the ocean, land and sky. Much of their success is due to the many new forms their skeletons have taken. A new coffee-table-format book, “Evolution” (Seven Stories Press), offers hundreds of gorgeous photographs of those forms, as diverse as bats with fingers thinner than pipe cleaners and rhinos with skulls as stubborn as boulders.
Accompanying the photographs, by Patrick Gries, are essays by Jean-Baptiste de Panafieu, a French biologist and author. Dr. de Panafieu offers a guided tour of the skeletons, suggesting how to read in them the history of life and the patterns of evolution. New forms have evolved from old ones. Stubby amphibian feet have been transformed into hooves, bird wings and whale flippers. Yet many of the bones in those original limbs have not changed their relationship to the rest. They have just been stretched, flattened or reduced to vestigial knobs. Along the paths of evolution, the vertebrate skeleton has been transformed into similar forms many times over — aardvarks in Africa and anteaters in South America.
The bone of skeletons is one of many tissues in our bodies, made like the rest from instructions in our DNA. Those instructions carry their own clues to the history of vertebrates. Simply changing how long a gene continues to produce proteins during the growth of an embryo can help produce radically different forms — making the hind legs of the ancestors of whales practically melt away, for example. But the transformation of this genetic recipe can be dauntingly abstract. Skeletons, as “Evolution” demonstrates, provide evidence for the history of life both hard and beautiful.
Copyright 2007 The New York Times Company. Reprinted with permission.