"Mutants" satisfies genuine curiosity while transcending prurience, giving us a good look at the amazing prospect unfolding before us as we decode the human genome. It's Leroi's first book — and a marvelous accomplishment. May there be many more.

Seattle Times

'Mutants' unravels mysteries of fate

"The monstrous, the strange, the deviant ... reveal the laws of nature. And once we know those laws, we can reconstruct the world as we wish."

Elegantly paraphrasing 17th-century philosopher Francis Bacon, author Armand Marie Leroi gives a completely convincing justification for our interest in what were once known as "prodigious births."

Leroi's "Mutants: On Genetic Variety and the Human Body," also acknowledges the existence of less-intellectual attitudes: the gawking curiosity of circus-sideshow audiences, the intolerance condemning any visible difference as a sign of God's wrath.

Sticking to the high ground, Leroi commands an excellent view of a subject at times disturbing, even horrifying; at other times oddly entrancing. Following a brief summary of modern genetics, Leroi fills us in on the often quaint histories of embryology (the study of the embryos) and teratology (the study of monsters). He then devotes eight chapters to eight major classes of mutations.

"A Perfect Join (on embryos)" deals with probably the most familiar human mutation: conjoined twins, formerly known as Siamese twins. In this first chapter, Leroi introduces us to a protein with the whimsical name of "noggin," one of several responsible for organizing embryonic cells into skin, neurons and other specialized tissues. Noggin, cerberus, dickkopf and the genes that switch them on and off are only part of the solution to the mystery of conjoinment, however.

Turning to the case of a nontwin, a French soldier whose internal organs were reversed (his heart closer to the right, liver on the left), Leroi connects this deviant anatomy with the man's poor sense of smell and his childlessness to explain the rest of the story.

"The Last Judgment (on first parts)" looks at a truly grotesque mutation: cyclopia, the condition of being born with only one eye. Here the book's copious illustrations come into their own. There's a sylvan landscape inhabited by the Cyclops of classical Greece and a less picturesque drawing of a cyclopic infant attributed to Leonardo da Vinci.

"Mutants" reproduces more than 60 woodcuts, lithographs, drawings, paintings and photographs, and many are not for the squeamish. A few plates in the chapter on hermaphroditism and other gender-related disorders are unabashedly graphic. Yet overall, the book's illustrations match Leroi's tone, capturing his awe at the incredible variations the human body is prone to and his compassion for those suffering from the cruelest of these variations.

In the midst of all this serious subject matter, Leroi also entertains readers with references to Hemingway's polydactylous cats and the "wistful propaganda" tying male-pattern baldness to virility. He compares redheads' lack of melanin to the eyelessness of blind cave fish. He theorizes that age and death are caused by specific mutations, and he wants to know how we choose and focus on the statistically insignificant genetic markers by which we classify a person's race.

Entertaining facts, thought-provoking speculations and step-by-step accounts of scientific discoveries are backed up with profuse end notes and a lengthy bibliography. A glossary would have been a nice addition; for some of us it's a struggle to remember the difference between an allele and a blastocyst. Still, that's a small omission in a book so richly rewarding.

"Mutants" satisfies genuine curiosity while transcending prurience, giving us a good look at the amazing prospect unfolding before us as we decode the human genome. It's Leroi's first book — and a marvelous accomplishment. May there be many more.

Nisi Shawl
Seattle Times (January 18, 2004)