BIOLOGICAL CLOCKS

BIOLOGICAL CLOCKS: Your Owner's Manual
Sue Binkley
Harwood Academic Publishers, 1997
Amsterdam, The Netherlands
http://www.gbhap.com
220 pages, paperback, US $19.95
ISBN 90-5702-534-5

Reviewed by Lynne Lamberg

One can imagine college students enduring long lines to sign up for Sue Binkley's biology classes. She comes across as unpretentious, droll, and wholly engaged by the workings of biological clocks.

An "owner's manual," however, this is not. "This is not a self help book; and it's not a textbook," Binkley tells readers straight out. "There's a little information, she allows. "Maybe it will interest you."

There is, in fact, a lot of information. A ton of information. The attentive reader will gain familiarity with a wide range of biological rhythms' terminology and concepts. As at any smorgasbord, readers might do well to sample a bit, and sit a while before returning for more.

Binkley, now retired after a quarter-century of teaching, begins her discussion of body clocks at the concentric rings of standing stones, banks of earth, and ditches that make up Stonehenge, in southwestern England. Its time-conscious builders 5000 years ago, she speculates, might have used a circle now marked by 56 holes where posts probably once stood, to count the days and nights of the 28-day human female menstrual cycle.

Women might have used the same circle to tell whether they were pregnant: if they started counting on the first day of menstruation, assigned one day to each point on the circle, and went all around it without having a period, they most likely were expecting.

Binkley tells how scientists study daily patterns of activity or coloration as indicators of biological rhythms. Earthworms crawl 10 centimeters in a little over 21 seconds at midnight, she reports, but cover the same distance in less than 17 seconds at 7 a.m. Chameleons are green at night but change colors in the daytime, depending on the background on which they rest.

She explains how laboratory researchers reset clocks by changing the length of exposure to light and dark or environmental temperature, and by giving clock-activating substances, such as melatonin.

In a chapter on human rhythms, she discusses daily and seasonal changes in mood, insomnia, jet lag, and shift work. "Birds of a feather clock together," Binkley asserts. But in humans, she says, individual differences in daily behavior are the norm.

She dubs Ted Kaczynski, the Unabomber, as "The Solstice Bomber." Of the 17 attacks for which he was found guilty, she notes, 9 were in May and June, and 4 were in November and December, near the longest and shortest days of the year. She leaves it to readers, however, to speculate on the meaning of this pattern: perhaps some tie between the presence or absence of bright light and mood.

Binkley reports that she wore a computerized wrist activity monitor for several years, removing the device only for showers and swimming. Alas, she summarizes her findings in only one paragraph, mentioning that menstrual and annual changes occurred, but not telling the details. (She has published on this topic in scientific journals and includes these citations in the book's 192 references.)

In a series of appendices students will find useful, Binkley includes a list of societies for the study of biological rhythms, journals, software, and an annotated bibliography. She also includes charts and instructions, albeit complex ones, for recording one's own circadian rhythms.