Physicist Lindley (The End of Physics, 1993) and DeSalle, a DNA-in-amber expert at the American Museum of Natural History in New York City, have a fine time taking to task the tangled web Michael Crichton has spun in his Jurassic Park books and movies. Rather than producing a smug put-down, however, they provide a fine guide to the perplexed on genetic engineering and evolution. For a start, they point out that warm tropical islands off the coast of Costa Rica may have Technicolor charm but are the wrong places to look for really old amber (65 million years at least, if you want dino DNA). You're better off in New Jersey! But that's a minor detail. All of the clever gene amplification methods today would not be enough to reconstruct all you need to know to fashion your favorite brontosaurus or velociraptor from what could be recovered from a mosquito in a chunk of amber. To understand why, the authors review what we know about fossils, about dinosaurs, and about manipulating DNA. They explain how to extract DNA, map and sequence it, identify genes, and make comparisons across species. Even presuming that the DNA recovered miraculously contains a full dinosaur recipe, the next hurdle would be to puzzle out where to grow it; you need a receptive egg and egg-layer. And other problems follow: How would a dinosaur, without parents, learn to behave like a dinosaur? There is, perhaps, a little overkill here, as the authors indulge in the numbers game of how much land (and food) it would take to maintain the dinosaurs described in the books. Not that they are total skeptics: Recent headlines, after all, have demonstrated the spectacular possibilities of cloning. If, as they say, everything in life is a matter of timing, DeSalle and Lindley could hardly have brought out a book at a more propitious time.