- The Washington Times - Saturday, November 1, 2003

TEARS OF THE CHEETAH: AND OTHER TALES FROM THE GENETIC FRONTIER

BY Stephen J. O’Brien

Thomas Dunne/ St. Martin’s,TK, TK

REVIEWED BY CHARLES ROUSSEAUX

Stephen O’Brien is a molecular cryptographer. Like an analyst at the Defense Intelligence Agency or the Central Intelligence Agency, he decodes hidden messages — but the messages he looks for are hidden in strands of DNA. In his splendid new book, “Tears of the Cheetah,” Mr. O’Brien offers 14 tales deciphering the hidden history of animals and their diseases — usually for the benefit of man — from his work as head of the Laboratory of Genomic Diversity at the National Cancer Institutes.

DNA’s four fragile letters have been copied countless times over many thousands of years, changing as species have separated and evolved, always under the killing pressure of natural selection. Most DNA changes occur at a calculable pace over set time intervals. As a consequence, an animal’s genetic record is also a historical record of its species, showing both its previous brushes with extinction and the minor genetic changes that allowed it to endure.

Moreover, because most mammals have large stretches of DNA in common, diseases afflicting one species often have counterparts in another — including in man. The same is true of potential cures. However, it is only recently that scientists have learned how to decode the latent messages in genetic records, and Mr. O’Brien is among those who led the way.

Each of the remarkable discoveries of Mr. O’Brien and his research teams is covered here. That makes for quite a menagerie. The author is the world’s foremost expert on feline genetics, but he has analyzed the genetic records of species ranging from humpback whales to pandas.

Perhaps Mr. O’Brien’s most important finding was that cheetahs across the world are almost identical — as closely related as deliberately inbred strains of lab mice. Since cheetahs mate randomly in the wild, the best explanation is that at some point in the past, there was a catastrophe that wiped out most of the species.

The survivors of that “population bottleneck,” to use the author’s term, interbred with each other, magnifying genetic defects. These microscopic changes have had macroscopic results, seen in the reproductive defects that cause cheetahs to have high rates of infertility as well as their great susceptibility to infectious diseases.

Other chapters unravel equally intriguing mysteries.

Mr. O’Brien relates how he discovered that Florida’s endangered panthers, like cheetahs, are also highly inbred. He tells how he determined that feline immunodeficiency virus (FIV), the cat’s equivalent of HIV, has infected a wide variety of feline species (including nearly 70 percent of Serengeti lions). However, it is killing few of them, thanks to evolving genetic changes. The author’s research teams also discovered that giant pandas are related to bears, not raccoons, as had previously been thought.

Mr. O’Brien helped some of his colleagues determine the history of the humpback whale, information they later used to prove that meat from several endangered cetaceans (including the humpback) was being sold illegally at Japanese markets.

Mr. O’Brien and his researchers even helped solve a murder. Using genetic “paw prints,” they traced cat hairs found on a jacket spattered with the victim’s blood to Snowball—a cat owned by the murderer’s family. Their DNA analysis provided the only physical link between the victim and the murderer, a link that later led to a conviction.

Each of these tales is packed with information, making for a worthwhile, if time-consuming, read. Although Mr. O’Brien covers quite a bit of technical ground, he does so with a surprisingly light touch — those without a scientific background shouldn’t fear the terminology. Any reader who gets lost in the language can refer to a brief, handy glossary.

One theme that emerges from the book is that nature is not a nice place — regardless of the machinations of man. An outbreak of bloodsucking flies decimated the leonine residents of the Serengeti Preserve’s Ngorongoro Crater in the early 1960s. About 12,000 years ago, a still unknown agent — possibly climate change, infectious disease or human hunting — eliminated three-quarters of the large animal species on several continents. It also pushed cheetahs to the brink of extinction.

As Mr. O’Brien notes of animal populations faced with ravaging diseases, “These species have no health insurance, no HMOs, no emergency rooms — only natural selection.”

Admittedly, man mucks it up more often than not, particularly members of human bureaucracy. Mr. O’Brien relates how he almost wasn’t allowed to testify about Snowball’s DNA because of ill-founded concerns from the NCI’s ethics office. His team’s genetic sampling of lions in the Ngorongoro crater was almost stopped cold by a princess from the Netherlands who thought that they were “molesting” the lions. There were several political fights over differing conservation strategies for Florida panthers.

Although the book has a strong conservationist tone, this rarely becomes shrill. Mr. O’Brien merely points out, again and again, the lessons that animals teach men through their diseases and disorders. While it covers everything from the conservation of endangered species to advances in gene therapy, the book remains extremely even-tempered and accessible.

There are only a few diagrams, printed in the volume’s single short insert of black and white photos. (They’re worth a peek, if for nothing more than the picture of a cat staring at its own genome.)

One unfortunate consequence of the book’s intense focus on science is that few of the characters are fleshed out. Most have bit parts at best. For instance, Mr. O’Brien’s “pretty and always smiling wife” steps onto the stage for about a paragraph, and then exits with nary a word. There are a few other minor problems as well. The chapters on AIDS become a bit jargony, and there’s a fair amount of self-congratulation throughout the volume. Yet considering the length of Mr. O’Brien’s tenure with the National Institutes of Health and his paper trail of published articles, it would have been easy for him to do quite a bit more damage on that front.

On the whole, the book does a first-rate job of describing how the decoding of animal DNA is leading to better health for both beasts and men. It’s a nonfiction “Da Vinci Code” for the conservationist, but scientists, spies and those somewhere in between will also find it engaging.

Charles Rousseaux is an editorial writer for The Washington Times.


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