Sam Kean’s The Violinist’s Thumb hits on multiple levels. It tackles the big basic questions: “How Do Living Things Pass Down Traits to Their Children?” and “What Kinds of Information Does DNA Store?”. It explores the big not-so-basic questions: “Why Did Humans Almost Go Extinct?” and “How Deep in Our DNA is Artistic Genius?”. And it covers the small details. Kean lets readers know that as little as one ounce of polar bear liver can be fatal to humans, that there is a gene known as the sonic hedgehog gene, and that Walt Whitman’s brain weighed a mere 44 ounces (the human average is 50). In short, Kean tackles all things genetic, from the length of a single gene of DNA (approximately six feet) to cloning (and even shows a picture of Dolly the sheep getting a checkup).
He begins with the history and tells the stories of the pioneers—some well-known names like Charles Darwin and Gregor Mendel and some less familiar figures—such George Gamow, founder of the RNA Tie Club. And who knew scientists could be so witty, but considering “fruit fly genes include groucho, smurf, fear of intimacy, lost in space, smellblind, faint sausage, tribble (the multiplying fuzzballs on Star Trek), and tiggywinkle”, clearly scientists like to have a little fun.
After the scientists, Kean moves on to people who have interesting or unusual DNA stories, such as Tsutomu Yamaguchi. Yamaguchi survived the bombing of Hiroshima in 1945 and immediately headed home to Nagasaki. He survived that bombing, too, but Kean suggests Yamaguchi’s short term suffering—vomiting, burned skin flaking off, loss of hearing, flesh glowing “raw red ‘like whale meat’”—would only be matched by “the long term agony… as mutations slowly began surfacing”.
In later chapters, Kean ponders “what happened to Neanderthals”. One possible answer: “Perhaps only Neanderthal men bagged human women, who then left with their clan”. He also examines the relationship between brain size and intelligence and analyzes our obsession with diagnosing the dead: “All of them are past helping, so it’s not clear why we bother. But whether it’s Chopin (cystic fibrosis?), Dostoyevsky (epilepsy?), Poe (rabies?) Jane Austen (adult chicken pox?), Vlad the Impaler (porphyria?) or Vincent Van Gogh (half the DSM), we’re incorrigible about trying to diagnose the famous dead.”
He then moves to the fictional, noting that Darth Vader has been “confidently diagnosed” with borderline personality disorder and “Sherlock Holmes with autism”. And going back to the non-fictional sort, of course, Kean discusses violinist Niccolò Paganini’s “genetic disorder that made his hands freakishly flexible”.
Each chapter focuses on a different question, and answering questions is the primary purpose of the book. In the introduction, Kean announces (although it almost sounds like a warning) that “This might as well come out up front, first paragraph. This is a book about DNA—about digging up stories buried in your DNA for thousands, even millions of years, and using DNA to solve mysteries about human beings whose solutions once seemed lost forever”. Of course, not all questions can be answered—how could Yamaguchi, after surviving both Hiroshima and Nagasaki, live until 2010 (he died at age 93 of stomach cancer)? Kean can only “hazard educated guesses”.
For the most part, though, Kean answers questions and uses stories—from John F. Kennedy’s possible Addison’s disease to Ilya Ivanov, who created zonkeys (a zebra donkey mix)—to make these answers memorable.
But the most memorable story of all isn’t about any of the famous people Kean discusses or any of the historical figures. It’s about Kean himself. In the beginning of the book, he relates that he recently underwent genetic testing and seems particularly concerned that Parkinson’s might be “lurking” in his genes. After all, isn’t this what most of us want to know—what’s hiding in our DNA? Information about King Tut or Abraham Lincoln is interesting. Debating the wisdom of cloning is interesting. In this book, even fruit flies are interesting. But when it’s our DNA… well that’s a different story, and perhaps that’s why Kean’s story might be the most inspirational of the lot.
At the end of the book, Kean reveals the results of his genetic screening, and after some initial cheering, he finally concludes “I enjoyed having my DNA sequenced and would do it again, but not because I might gain a health advantage. It’s more that I’m glad I was here, am here, in the beginning.”
Can The Violinist’s Thumb make us all that relaxed about our own DNA? Perhaps not, but the humor, style, and stories found in the book will make DNA and genetics accessible to all—even the “scientifically challenged”.