This Book Was Made for Walking

How X Made Us Human” has been an evergreen trope for publishers. There are many answers on offer. We are human because we ate meat. (Yes, really.) Or because we were stone-cold killers. Or because the left hemisphere of the human brain evolved with a specialization for language. And so on. Often, it turns out, the assertion made in the title or subtitle is considerably modified, qualified, nuanced in the course of the book in question—the idea being to grab the reader with a provocative claim that will compel attention. These informed speculations are not irrelevant to Christians, all of whom believe that God created humankind but many of whom resist (as I do) the Young Earth Creationist account of what that claim entails.

Jeremy DeSilva’s First Steps: How Upright Walking Made Us Human drew my attention because I am interested in this genre, but also for another reason: I walk a lot, and I love to read books about walking, from many different angles. It turns out that DeSilva has written one of the most interesting “science books” I’ve read in the last five years and one of the most interesting “walking books” over the same span.

There are several recurring templates in contemporary science writing. One of these is to tell the story at hand in small bits, with many rapid changes of scene, and to flavor exposition of the core subject with personal asides and local color. Not either/or, in other words (either “scholarly for nonspecialists” or “pop”), but both, the goal being to keep the reader turning the pages. DeSilva, a paleoanthropologist at Dartmouth, is a master of this style; the reader will not be surprised to learn, from the back flap of the dust jacket, that from “1998 to 2003 he worked as an educator at the Boston Museum of Science” and that he “continues to be passionate about science education and travels all over the world, giving lectures on human evolution.”

There are times when this passion to keep the reader engaged veers dangerously close to self-parody. In Chapter 3, wittily titled “‘How the Human Stood Upright’ and Other Just-So Stories About Bipedalism,” we come across this paragraph:

Molecular anthropologist Todd Disotell greeted me as I stepped off the cramped elevator on the fourth floor of 25 Waverly Place on the New York University campus in Greenwich Village. Disotell is short and fit, looking much younger than his fifty-five years. It was a cold, raw April day, but Disotell wore brightly colored shorts, canvas loafers, and a King Kong T-shirt. His short sleeves revealed tattoos of Darwin’s famous “I think” line drawing of a family tree on his right forearm and Bigfoot on his left biceps. He had shaved his mohawk and instead sported a buzz cut, goatee, and orange-rimmed glasses. Disotell is one of the world’s experts in anthropological genetics.

I can understand how hard it would have been for DeSilva to leave this juicy description on the cutting room floor, even though the “countercultural scientist” has become a hoary cliché. Reality isn’t fastidious; I’m sure Disotell is just as he is described here. And DeSilva uses this bit of local color to lead into a discussion (with Disotell soon quietly moved offstage) speculating “why upright walking was beneficial” when, millions of years ago, “terrestrial bipedalism evolved in an [African] environment that was shifting from vast forests to open savannahs with patchy clumps of forest.”

This line of investigation, continued at intervals and concluded in the final chapter, leads to the last paragraph of the main text, which emphasizes the sharp contrast between DeSilva’s perspective on our lineage and that of many who are struck above all by our propensity for violence: 

It is time to embrace the lessons the bones of our ancestors teach us and construct a new human origin story in which the evolutionary success of this extraordinary upright ape is attributed in large part to our capacity for empathy, tolerance, and cooperation.

Whether or not you agree with DeSilva, I think you will find his exposition absorbing (midwifery plays an unexpected role in his concluding chapter).

But interwoven with this main line of argument, which focuses on paleoanthropology, are threads having to do with walking, not in the immensely distant past but in the present—not least, the walking of the twins, Ben and Josie, observed firsthand by DeSilva and his wife, Erin. Don’t miss, in the section of illustrations, the “trail left by a thirteen-month-old toddler spontaneously walking for ten minutes in Dr. Karen Adolph’s developmental psychology lab at New York University.” (DeSilva’s account of Adolph’s work is among the most fascinating sections of the book.) And if you haven’t already been persuaded by accounts of the overwhelming evidence for walking’s benefits, perhaps DeSilva’s Chapter 13 (“Myokines and the Cost of Immobility”) and Chapter 14 (“Why Walking Helps Us Think”) will do the trick.

A closing suggestion. Sometime, sometime, at last, there will be more opportunities for in-person lectures and similar events. If you have any influence at this or that institution, this or that university, and so on, consider inviting Jeremy DeSilva to talk on the subject of this book. I haven’t heard him, but on the evidence of First Steps, he is likely to be a terrific speaker. And don’t delay; I suspect that before long, he will be completely booked for the foreseeable future.

John Wilson is a contributing editor for The Englewood Review of Books and senior editor at The Marginalia Review of Books.

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