Chekhov observed that if you write a story about a man, a woman, and a beetle, the story is always about the man and the woman. Maybe it was an ashtray instead of a beetle. The point is that any story that involves humans is always about the things we do and don’t do to each other. The rest is, if not quite landscape, damn close.

We shouldn't feel bad about caring most about each other. If beetles were writing the stories, they would all be about beetles, perhaps with a giant human foot as threatening landscape. We have evolved senses that are finely tuned to noticing each other and, only secondarily, finding the right fruit and avoiding, for example, venomous snakes. So when it comes to describing the world, we approach the endeavor with a view centered on ourselves, then on animals like us or useful to us. The beetle, even if it lands in our hair, is low on the list.

Nowhere are our biases more consistently problematic than in our struggle to name and categorize life. (Think, for example, of the misguided ladder of progress on which humans are, inevitably, placed on the top rung.) In 

, science writer Carol Kaesuk Yoon describes the long battle to wrest truth from perception in our attempts to categorize life, from Carolus Linnaeus (1707–78), the forefather of modern taxonomy, to the present day.

Taxonomy—the naming and categorizing of life—is one of the oldest human pursuits. It is the necessary endeavor, an urge even, to distinguish and group the kinds of life so that once named and ordered, they might also be understood. In considering the history of taxonomy, Yoon frames her argument around the narratives of several dozen biologists, more often than not male and an eensy bit megalomaniacal. Their stories are rich and interesting and full of jaw-dropping hubris. Take, for example, Robert Sokal, who in 1953 bet a colleague a six-pack that on a particularly insightful morning he had discovered the new and best way to organize life, based on statistics rather than experience and intuition. He won the beer.

Although scientists drive Yoon’s story, the main character is an 

 You would be forgiven for thinking that an 

 was a small bird indigenous to central Europe—the word, though, is ordinarily translated from German as “environment” or “setting,” Yoon’s definition is more nuanced. As she describes it, an 

 is the world as it is perceived. Every individual of every species has an 

is framed primarily by chemical senses. Our human 

 evolve along with our senses, which struggle to notice the things most relevant to our survival.

Yoon argues that the central battle in taxonomy is between truth—the world as it is—and the 

. Historically, humans named the things around them based on what they saw, a dose of local culture, and a set of relatively consistent and near-universal rules (e.g., that each species has a two-word name, whether “fruit fly” or Drosophila melanogaster). Traditional peoples the world over continue to do so. But scientists have sought to devise a true system for categorizing nature. The tension lies in the fact that they do so through senses that did not evolve to find truth. (There is no fitness advantage in looking for truth. In fact, if you look at the reproductive fitness of scientists, there may be some cost . . . ) Instead, we evolved to keep an eye out for sexy cavewomen, predators, or tasty fruits.

Yoon concludes by asking whether there are costs to this quest for truth. Where once taxonomy was based on experts’ experiences and opinions, today it is based on data. Fewer and fewer scientists are well acquainted with the life histories of the organisms they study. They rely on what DNA analyses and computer outputs tell them. Yoon suggests that while these superficially less biased approaches have increased our collective knowledge, they may have done so at the expense of what each of us knows individually. Specialists look through ever narrower lenses at the world in greater and greater depth, even as they believe themselves to be, each day, coming to truer visions of what is out there breeding, feeding, and dying among the weeds. Our ancestors looked at a snake and called it by the name they had given it, a name every child knew. Many biologists today look at a snake and wonder if anyone knows a relevant expert who might be able to identify it.

 is rich in insight, characters, humor, and even, yes, truth. The book is almost good enough that if there were a man and a woman in a room with it, the story would still be about the book.

 is an ecologist at North Carolina State University and the author of

Every Living Thing: Man's Obsessive Quest to Catalog Life, From Nanobacteria to New Monkeys

"Naming Nature: The Clash Between Instinct and Science" 

Beetle_collection.jpg

The central battle in classifying the world around us is between objective truth and the framework through which we see the world, our umwelt. 

Stalking the Umwelt

It's late, and, as always, I have lots of things I’d like to do before I go to bed. I don’t sleep much. I enjoy being awake. My dreams are quiet, but my days are full of things to explore, the treasures of ordinary life. So when I began to read Till Roenneberg’s 

, a book whose dust jacket mentions sleep and biological clocks, I was hoping to find a passage clearly stating that those who sleep less are happier and wiser, and live longer, or at least are more interesting to talk to at parties. I didn’t find it, but the book was fascinating, and so I read on, and now, at 11 p.m., I have begun to write.

The story of the daily rhythms of our bodies begins with the study of the skies. In 1729, French astronomer Jean Jacques d’Ortous de Mairan found himself wondering how the Earth’s spin affected the species around him. He kept a mimosa, one of his favorite plants, on a windowsill near his desk. Leaves furled, it slept even when he could not, and so he decided to stay up a little longer and study how it knew what to do during the day and night. De Mairan put his plant in the cupboard. There it did as it had always done, opening all of its leaves simultaneously at daybreak and closing them at night. Somehow the plant knew what was going on outside the cabinet. That was the end of de Mairan’s experiment; he left the rhythm of mimosas observed but unexplained.

In 24 easy-to-read chapters, Roenneberg proposes to explain what de Mairan did not and to tell us why the circadian rhythms in our bodies matter in our daily lives. Other books have dealt with our biological clocks, but Roenneberg focuses on the ways in which societal pressures seem to be leading us to disregard our clocks, at considerable cost.

Your body is set, more or less, on 24-hour days, but just when those cycles begin and end is “entrained” by light. Receptors in your eyes (apart from those rods and cones you learned about in school) tell you if it is day or night. These receptors are not wired to your conscious brain, but to a special part of the subconscious brain called the suprachiasmatic nucleus, in essence, your timekeeper. The timekeeper signals the pineal gland what to say to the body via hormones such as melatonin (whether it be “night, night, night” or “day, day, day”). At night our temperature decreases, and our cortisol production declines. Even our metabolism waxes and wanes. All of this happens without us ever thinking about it, the tides of our bodies pulled by invisible and very ancient forces.

Roenneberg spends a lot of time discussing what are known as chronotypes—categories of individuals who differ in their sleep rhythms, whether because they need more or less sleep or tend to be early wakers or late wakers. But as Roenneberg points out, such chronotypes do not really exist as categories. Instead, like other complicated attributes of living things, the variation among individuals is continuous (and relatively modest—we vary less in rhythm than in height). Most people are neither lark nor owl but human, falling somewhere along a continuum. Most of us need between seven and a half and eight and a half hours of sleep (but get less). Some turn in early, others late, though very few people wake up before five or after ten.

More to the point, while we differ in our timing, the biggest differences in our degree of larkiness have to do with age. Teenagers are the weirdest ones. They are innately late risers, getting up (in the absence of alarm clocks and parental intervention) several hours later than younger kids or adults. Get them up too early and they are mean, silly, and not as clever as they might be later in the day. As we age, we rise earlier and earlier.

Roenneberg not only explains our daily cycles but also asks us to re-evaluate the extent to which we allow society to push us toward longer days and artificial waking times. He argues that it behooves us to rewild our cycles and live in a way that recognizes our natural rhythms, whether that means allowing teenagers to wake up later, living like larks or owls if that is our nature, or just sleeping more.

I like being awake. From Roenneberg’s perspective, spending more time awake than I should is a sort of vice I should try to combat. He is probably right, but I find solace in noting that de Mairan discovered circadian rhythms while working so late at night he could barely hold his quill. Meanwhile, I better wrap this up because I see it is now 4 a.m. and the damned larks, those early risers, have just begun to sing.

, a biologist at North Carolina State University, is the author of The Wild Life of Our Bodies: Predators, Parasites, and Partners That Shape Who We Are Today (2011) and Every Living Thing: Man’s Obsessive Quest to Catalog Life, From Nanobacteria to New Monkeys (2008).

Internal Time: Chronotypes, Social Jet Lag, and Why You’re So Tired

 by Till Roenneberg, Harvard University Press, 272 pp. 

11047169994_debcf51f59_k.jpg

The story of the daily rhythms of our bodies begins with the study of the skies. 

Rob Dunn