Excerpt: Sam Kean’s ‘The Violinist’s Thumb’

If you’ve ever wondered where a certain talent or preference comes from, perhaps it’s time to take a look at your DNA. That’s exactly what science writer Sam Kean has done in his latest, The Violinist’s Thumb. Kean provides a closer and provocative view into just what makes humans tick by studying our genetic makeup and tying it into our behaviors.

It’s no surprise that Kean has delivered another stellar look into science, as his last book, The Disappearing Spoon, was a New York Times bestseller. In a starred review, we called Kean’s new book “an impressive narrative…[Kean] renders esoteric DNA concepts accessible to lay readers.”

Read more top new nonfiction this July.

Here, an excerpt from chapter one:

Genes, Freaks, DNA: How Do Living Things Pass Down Traits to Their Children?

Chills and flames, frost and inferno, fire and ice. The two scientists who made the first great discoveries in genetics had a lot in common—not least the fact that both died obscure, mostly unmourned and happily forgotten by many. But whereas one’s legacy perished in fire, the other’s succumbed to ice.

The blaze came during the winter of 1884, at a monastery in what’s now the Czech Republic. The friars spent a January day emptying out the office of their deceased abbot, Gregor Mendel, ruthlessly purging his files, consigning everything to a bonfire in the courtyard. Though a warm and capable man, late in life Mendel had become something of an embarrassment to the monastery, the cause for government inquiries, newspaper gossip, even a showdown with a local sheriff. (Mendel won.) No relatives came by to pick up Mendel’s things, and the monks burned his papers for the same reason you’d cauterize a wound—to sterilize, and stanch embarrassment. No record survives of what they looked like, but among those documents were sheaves of papers, or perhaps a lab notebook with a plain cover, probably coated in dust from disuse. The yellowed pages would have been full of sketches of pea plants and tables of numbers (Mendel adored numbers), and they probably didn’t kick up any more smoke and ash than other papers when incinerated. But the burning of those papers—burned on the exact spot where Mendel had kept his greenhouse years before—destroyed the only original record of the discovery of the gene.

The chills came during that same winter of 1884—as they had for many winters before, and would for too few winters after. Johannes Friedrich Miescher, a middling professor of physiology in Switzerland, was studying salmon, and among his other projects he was indulging a long-standing obsession with a substance—a cottony gray paste—he’d extracted from salmon sperm years before. To keep the delicate sperm from perishing in the open air, Miescher had to throw the windows open to the cold and refrigerate his lab the old-fashioned way, exposing himself day in and day out to the Swiss winter. Getting any work done required superhuman focus, and that was the one asset even people who thought little of Miescher would admit he had. (Earlier in his career, friends had to drag him from his lab bench one afternoon to attend his wedding; the ceremony had slipped his mind.) Despite being so driven, Miescher had pathetically little to show for it—his lifetime scientific output was meager. Still, he kept the windows open and kept shivering year after year, though he knew it was slowly killing him. And he still never got to the bottom of that milky gray substance, DNA.