Rhythms Of Life: The Biologicial Clocks That Control the Daily Lives of Every Living Thing

Rating:
Summary: Body Clocks vs. Mechanical Clocks
Review: For the first few million years of life, time was measured by sunrise and sunset. Now we have switched to clocks. But the biological clocks that are within all of us don't know how to read clocks. Breakfast, lunch and dinner occur at standard times. Tooth pain is lowest after lunch; proof reading and sprint swimming are best performed in the evening; labour pains more often begin at night and most natural births occur in the early hours; sudden cardiac death is more likely in the morning (from Chapter 1).

The study of biological clocks has gone on for a long time, but as a science is a fairly recent development. Research in just the last few years has dramatically altered the way scientists view them. This book is a snapshot of the way the science appears right now. The pair who wrote the book are a leading researcher in the field and a professional science writer. This is a good combination that gives good enjoyable writing combined with accurate reporting.

Rating:
Summary: The Protein Tick and the RNA Tock
Review: What do the disasters of the _Titanic_, the _Exxon Valdez_, Chernobyl, Three Mile Island, and the Union Carbide plant explosion in Bhopal all have in common? They involved human error, and they all happened when the humans ought, by biological fiat, to have been sleeping. We are ruled by our clocks now, but even in the unnatural world we have made for ourselves, we cannot get away from the natural clocks that our cells expect us to follow. Like almost all living things in the planet, from plants to bacteria to birds, we have "a biological clock that was first set ticking more than three billion years ago." In _Rhythms of Life: The Biological Clocks that Control the Daily Lives of Every Living Thing_ (Yale University Press), Russell G. Foster, a professor of molecular neuroscience, and Leon Kreitzman, a writer and broadcaster, have examined the investigations of a relatively new science, chronobiology, to show just how much sway natural time has over us and other organisms. It isn't just a tale of sleepy people in control making bad judgments, although cognition and prudence do have their daily cycles. We tend to have babies (natural birthing) in the early mornings, and heart attacks in the later morning, and lovemaking around 10 p.m. Physical coordination, liver metabolism, body temperature, heart rate, kidney function, and much more all are paying attention to the biological clock, and when we jump time zones or do shift work, we do so at our peril.

Many of these cycles are specifically examined here, along with the historical hunt for the biological roots of the rhythmicity. A couple of the chapters dealing with the dance of molecules will be daunting for those uninitiated into the basics of cellular biology, but they do well to show the intricacies of the molecular mechanisms and the depth of work that has been done in this field. There are not just daily rhythms, but annual ones. Migratory birds the whole world over know when to start their travels north or south; they do so not by counting the days or paying attention to when the weather changes, but by regulation from the annual changes of lengths of day and night. Plants cannot migrate, but they are regulated by day length, too; wheat flowers, for instance, when the days get long enough, and barley does so when the days start to shorten. The almost universal attention that species pay to daily or annual changes indicates that success comes from being able to predict when winter, or summer, or nightfall, or other events, are coming, and from timing leaf drop, coitus, or swimming upstream to meet the optimum times and conditions. Evolution has selected the species that are best able to predict the future.

In the famous experiments where humans lived in caves or other light-deprived environments, with no capacity to tell time, they eventually locked into their own cycles of a little more than 24 hours. Like most creatures, we have an internal daily rhythm which is not exact, but only approximate; the day night cycle (or for us, such cues as an alarm clock) "entrain" the internal cycle and keep it synchronous with the rest of the creatures on Earth. There are mutant rats and flies who have cycles that are too long or too short, and researchers have productively transplanted brain parts to find out where the actual clocks are. Chronobiologists (a term that even some chronobiologists think of as pompous) are not just doing ivory tower investigations. There are many practical implications of this sort of work. Breast cancers, for example, have an annual pattern of increased and decreased growths, and so searching for the cancer would be more productive at certain times of the year. Chemotherapy for cancers involves poisoning the cancer cells with drugs that are also poisons for regular cells, but cancer cells, with their out-of-control growth, lose their rhythm of growth and division that normal cells retain. Thus it is possible that administering anti-cancer drugs at the time of day when they will interfere the least with the normal cells could reduce the worrisome side effects of the drugs. Asthma is most prevalent at night; medicine for it would be best taken in higher doses at nighttime, rather than every eight hours. The timing of doses in some cases may be as important as what the doses contain. The authors have given a detailed but readable introduction into a new science that will have increasing importance for human health as more is learned.