Forget the meaning of life; we need a definition of it
A few months into the pandemic, my girlfriend and I made a horrifying discovery in our bedroom. A mossy, bone-white substance was - and we could imagine no other word for it growing along the inner edge of one window. Already besieged by a viral threat from without, we feared we were now at war with some other invader within. We went at it with the most abrasive cleaning products we had on hand, shaking and queasy, scrubbing until it had vanished.
Only the next evening as I was closing our heavy curtains did I realize how fully we had misled ourselves. The tendriled thing that spread across the aluminum frame was nothing other than linty fuzz that had been knocked off the backside of the blinds. Where we thought we had discovered new life, we had merely found evidence of a home repair in the offing.
As Carl Zimmer demonstrates in his new book, “Life’s Edge: The Search for What It Means to Be Alive,” the history of biology is peppered with such misapprehensions, many of them made by eminent researchers. Take Thomas Huxley, an early disciple of Darwin who became convinced in the 1860s that the seabed was blanketed by a living protoplasmic slime that he dubbed Bathybius haeckelii. Only later did he learn from the investigations of other scientists that Bathybius was not organic. It was instead, Zimmer writes, “a jellylike byproduct of chemical reactions that took place in the jars” in which the ocean-floor samples were stored. Decades later, John Butler Burke became temporarily famous, Zimmer tells us, after the physicist claimed he had used “radium to create life from lifeless matter” in sterile broth, a small army of mutating shapes that he dubbed “radiobes.” It was a thrilling discovery at first, but when another researcher attempted to reproduce Burke’s results he found “that the ‘cells,’ or radiobes, are nothing but little bubbles of water produced in the gelatin by the action of the [radium] salts upon it.”
While Huxley and Burke went wrong, both did so in the attempt to make sense of life itself. Though his methods are journalistic, Zimmer takes on a similarly sweeping project in this book, which seeks to show why biologists “still cannot agree on the definition of life.” No mere catalogue of errors, “Life’s Edge” guides us from an abandoned mine in the Adirondacks where bats hang in homeostatic slumber to a California start-up attempting to synthesize RNAbased medications. With these and other examples, Zimmer illustrates why it is so difficult to arrive at a common understanding of where life stops and starts - and how we might one day reach it.