Take a piece of cardboard and cut out a shape roughly like that of a child's balsa-wood glider: two round-edged wings, a long, thin body and a stubby nose. Hold it over a group of just-hatched goslings and move it with the body forward: It will resemble the outline of a long-necked goose in flight, and the goslings will pay it no mind. But make one small change, moving it the other direction so that it now looks like the silhouette of a predatory hawk, and the goslings will scatter for safety in an instant. Instinct, the hard-wiring of behavior, is a fascinating thing, and a lot more comfortable to believe in in a species other than one's own. Jonathan Weiner's "Time, Love, Memory" examines unsettling developments in 20th-century molecular biology -- specifically, discoveries about the genetic programming of behavior -- that demonstrate that instinct controls the human being as fully as it does the gosling.
Weiner has a penchant, already demonstrated in his 1994 Pulitzer Prize-winning "The Beak of the Finch," for opening up the lives of scientists who have built deep relationships with communities of tiny creatures. The primary focus of this most recent work is Seymour Benzer, a Cal Tech researcher who works with fruit flies. In the mid-1960s, Benzer devised a simple system for examining the fly's attraction to light and found (among other things) that the odd fly that doesn't like to cluster around a bulb can pass that preference for darkness on to its offspring. It had been known since the early part of the century, also from studies of fruit flies, that inherited genes control the physical makeup of living creatures -- how our bodies look from the outside and the inside. But the discoveries of Benzer and his colleagues seem to show (they are not undisputed) that what we do with that body has also been at least partly passed along from our forebears, that "behavior is as much a part of the material world ... as the atoms within us." Since Benzer's first experiments, molecular biologists have been taking apart the cognition of time, the act of remembering and the urge to love.
Weiner is an able simplifier of the enormously complicated atomic theory of behavior, a field that Francis Crick, the co-discoverer of DNA, has described as existing on the "borderline between the living and the nonliving." On the other hand, Weiner has a tendency to overpraise, describing more discoveries than you can comfortably count as the most important of the century. And only a writer who is part science nerd himself would include descriptions of the mundane antics of people who haven't seen the outside of a lab in years and desperately need to. (They put movie posters from "The Fly" on their office walls and cross their eyes when people take their picture! What a bunch of kooks!) Such lab-coat sniffing wears thin fast. But anyone who can describe the "furrowed lobes of the human brain" looming "attractively ... like attainable mountains" deserves to be forgiven his occasional overenthusiasm.
Just as the obscure chalkboard scratchings of a few physicists early in this century gave birth to the most powerful military and political force of our time, Benzer and company's little-known research may affect substantial parts of our lives in the near future. If the human genome is fully mapped a decade or so from now, the possibility that you (or your employer or your insurance company) might be able to order up a map of your future travels through the land of disease is fraught with quite enough moral peril. But the potential for your upcoming devilish doings? If that's quantifiable, it is indeed time to run for the hills.