Sex Imperative Evolutionary Tale

An edifying, witty survey of sex in the animal kingdom, this primer begins by scrutinizing the extraordinary variety and adaptability in the sex lives of microbes, worms, squids, salmon, seahorses, penguins, elephants and other species. Sex, a practice highly costly in time and energy, has persisted among humans, a fact Maxwell attributes to its evolutionary advantage. With authority and a light touch, he discusses the role of sexual organs, other glands and the brain in human sexual growth and performance; possible hormonal and genetic factors in homosexuality; odors and lovemaking; and scientific advances ranging from microscopist Anton von Leeuwenhoek's discovery of sperm in 1679 to the cracking of the genetic code. Calling genetic engineering ``the agent of instant evolution,'' Maxwell, emeritus biology professor at California State University, concludes by assessing both the benefits and potential hazards of biotechnology in creating new forms of organisms. Photos. (May)