Felines & amp; silkworms & amp; produce ... oh my!

By THERESA HEGEL
VINDICATOR STAFF WRITER
"Shrinking the Cat: Genetic Engineering Before We Knew About Genes," by Sue Hubbell (Houghton Mifflin, $25.00)
What do cats and corn have in common besides the initial "c" and a predilection for "stalking"?
They, along with silkworms, apples and countless other species, have been genetically altered by humans.
Before you continue reading, take a moment to erase the picture forming in your mind of the scientist with crazy eyes, wild hair and white lab coat assembling an army of felines that grow on stalks and spin silken cocoons.
The alterations that transformed corn into a farming staple and domesticated cats were made before sheep named Dolly became a controversial subject. They occurred before we even knew genes existed.
Genetic tinkering: In "Shrinking the Cat," Sue Hubbell explains how humans have always tinkered with their environment to make it a more habitable, comfortable and just plain interesting place. In fact, she proposes a more accurate name for our species: homo mutans, the human that changes things.
Though humans have tinkered with the genetics of many plants and animals, Hubbell focuses her book on just four: cats, silkworms, corn and apples. She says that through selective breeding and cross-breeding, humans were able to bring out a species' appealing attributes and weed out elements that were less savory.
Nice kitties: For instance, smaller cats with a friendlier, less jumpy nature and more attractive appearance would have been selected for breeding. Domestication took most of the predator out of the cat; a modern house cat's brain is smaller and its adrenal glands are less active than their wild counterparts.
An interes ting point Hubbell makes is that though the genetic changes we made in different species rendered them more convenient and pleasing to us, they did not, in most cases, make the species more fit to survive in the natural world.
Ours is a sort of artificial, accelerated evolution, contrasting with the way species in the wild evolve gradually to gain an edge over their environment.
Hubbell notes that silkmoths have been bred by humans to have a "huge, heavy body" and "placid disposition." A silkmoth's huge body allows it to spin lots of silken filament, but its small wings can no longer support its body, and it is incapable of flight.
'Botanical monster': She also explains that "biologists think of corn as a 'botanical monster,' for its seeds, wrapped in unnaturally tight husks, do not disperse and plant themselves. And, even if a husked ear falls and is buried in the soil, the young shoots die because they are overcrowded."
Both species must rely on human care for their survival.
Hubbell blends a chatty, narrative style with lucid, scientific prose. The result is an enjoyable and unobtrusively instructive book. Tidbits from her own life are interspersed with easy-to-understand, scientific explanations.
Her thesis is simple, though hardly simplistic. In an attempt to calm people's fears of genetic engineering by turning to history, she contends that we have been genetic engineers for centuries. The problem is not necessarily that we tinker with our environment. Hubbell believes this is human nature. What is important when we tinker, however, is that we are aware of all the possible effects of our engineering and that we decide what limits to place on our actions.
"Shrinking the Cat" is ideal for people who may be interested in science but don't have an extensive background in the discipline.
Hubbell provides us with a highly entertaining antidote to the popular phobia of modern genetic engineering.
hegel@vindy.com