- The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code. By Sam Kean.
Science is a tough sell. Even science geeks who enter college intending to major in one of the STEM subjects (science, technology, engineering, and mathematics) drop like fruit flies when they get into the lab and realize how demanding the material really is. According to a story last year in the New York Times, 40 percent of STEM undergrads end up either switching majors or not graduating at all. That figure increases to 60 percent for pre-meds—twice the combined attrition rate for all non-science majors. The reason for the drop-off, according to Times reporter Christopher Drew, is that science is “just so darn hard.”
If it’s this difficult to sustain interest in science among people who are already interested, what’s a pop-science book author to do? Getting the general public to stick to a science-y subject can be a circus act, a matter of keeping lots of pretty shiny balls in the air so your reader’s eyes stay aimed in your book’s general direction. That means relying on traditional storytelling techniques—turning everything into a narrative, creating a bit of suspense and maybe a little melodrama. My literary agent once referred to it as “substance disguised as style.” (He used that formulation to explain, as gently as he could, why my own science books weren’t making it to the best-seller list.) Book authors have been negotiating the delicate balance between style and substance since the days of Paul de Kruif, the first modern science writer. In Microbe Hunters, published in 1926, de Kruif set the standard for how to convey the excitement and essential ideas of science to a lay readership. His breathless tales of fourteen swashbuckling scientists—from Anton van Leeuwenhoek, the inventor of the microscope, to Walter Reed, who helped conquer yellow fever—were filled with suspense, jealousy, and wild goose chases, a feat of bravura storytelling that reputedly sparked the career goals of a generation of future scientists and Nobel laureates. More recently, skilled practitioners of this high-wire act, such as James D. Watson (The Double Helix), Dava Sobel (Longitude, Galileo’s Daughter), and Rebecca Skloot (The Immortal Life of Henrietta Lacks), have dominated best-seller lists by using many of the same methods as de Kruif. They made their books lively and literary, and lots of good science got conveyed in the process.
The latest entry in this grand tradition is Sam Kean’s The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code. It covers everything you wanted to know about DNA, from the basics of genes and chromosomes to topics seemingly as far afield as a Canadian couple’s adventures living with 689 cats and the brutal deaths of a band of sixteenth-century explorers who were poisened by eating polar-bear liver. The book’s strength lies not so much in narrative as a hipper solution: chirpiness. Kean represents a generation of science writers, in their twenties and thirties, whose style is bloggy, sort-of-funny, amiable, and smart.
The best parts of The Violinist’s Thumb are when Kean investigates some of the most complex concepts in genetics. His description of the evolution of our forty-six chromosomes, for instance, is straightforward and lucid. If humans evolved from apes, why do gorillas and chimps have forty-eight chromosomes and we have only forty-six? His explanation of what happened to the other two relates to the concept of chromosomal fusion. About a million years ago, he writes, in a proto-human with forty-eight chromosomes, a fusion occurred between the twelfth and thirteenth pair (chromosomes come in pairs, and humans have twenty-three). The result was an individual with forty-seven chromosomes who could go about his daily life with no ill effects—that is, until he began to produce sperm. Kean takes us through the mathematical journey of a forty-seven-chromosome Guy who mates with a forty-seven-chromosome Doll, whose children, for the most part, die in utero because most of them were either missing a chromosome or saddled with a duplicate, “practically a cyanide capsule for an embryo.” There was only one chance in thirty-six that Guy and Doll would create an embryo that was not only viable, but had just forty-six chromosomes. (This might all sound confusing, but Kean makes the math look easy.) “And here’s the payoff: Junior and his forty-six chromosomes would have a much easier time having children,” Kean writes. “[B]ecause he has an even number of chromosomes, little Junior wouldn’t have any unbalanced sperm cells: each would have exactly the right amount of DNA to run a human, just packaged differently. As a result, all his children would be healthy.” As Junior’s children began having children, Kean writes, the fusion spread, and eventually forty-six chromosomes would dominate in homo sapiens.
The violinist of the title is Niccolò Paganini, a nineteenth-century virtuoso with incredibly flexible fingers, arms, hips, and thumbs. It’s a bit of a stretch to include him in a book about genetics; he’s here because whatever it was that made Paganini so rubbery was probably a genetic disease known as Ehlers-Danlos syndrome. He appears late in the book, right before a chapter about what Kean calls retro-genetics, the field of figuring out which genetic diseases might have plagued some notable historical figures. Short of exhuming their bodies and trying to retrieve and analyze the DNA, scientists are left to make their best guesses: Marfan syndrome for Abraham Lincoln, Addison’s disease for John F. Kennedy, porphyria for King George III.
“All of them are past helping, so it’s not sure why we bother,” Kean writes. “A gawking fascination with our heroes certainly explains some of this impulse, and it’s inspiring to hear how they overcame grave threats. There’s an undercurrent of smugness, too: we solved a mystery previous generations couldn’t.”
Even when it comes to heavy-duty scientific information, Kean uses a light touch. Take his explanation of epigenetics, molecular biology’s hot new idea. Epigenetics is the mechanism by which the environment changes the genes, affecting gene expression by turning certain genes on and off via two sets of chemicals: methyl groups that turn the gene off, and acetyl groups that turn the gene on. Epigenetics does not change anything about the actual DNA sequence, but only “how cells access, read, and use DNA.” Think of the DNA genes as hardware, he writes, and epigenetics as software.
Epigenetics has revived the notion that environmental influences can be passed from one generation to the next, an idea called Lamarckism that was discredited in the nineteenth century by the work of Mendel and Darwin. New research offers an epigenetic explanation for the phenomenon. One is a study conducted by Swedish scientists looking at the medical records from the hamlet of Överkalix on the Swedish-Finnish border. As Kean describes it, crop failures have always been a regular occurrence in this harsh terrain, leading to regular cycles of gorging and starving among the populace of Överkalix. The scientists traced the lineages of 320 locals for several generations and compared them to crop records, hoping to find a link between a mother’s nutrition during pregnancy and the long-term health of the child. They found no such link. What they did find, Kean writes, was a “robust link between a child’s future health and a father’s diet,” and even a grandfather’s diet, as long as the men had lived through a famine at some point in their lives.
It remained a mystery until the scientists looked more closely at the timing of the starvation. For men who had gone through famine years during their infancy, puberty, or young adulthood, starvation had no effect on their children or grandchildren. But if they had starved during the “slow growth period” between ages nine and twelve, their children and grandchildren lived on average thirty years longer than descendants of men who had gorged. At this age, Kean writes, “males begin setting aside a stock of cells that will become sperm. So if the slow growth period coincided with a feast or famine, the pre-sperm might be imprinted with unusual methyl or acetyl patterns, patterns that would get imprinted on actual sperm in time.”
This story represents what I like most about this book: the clear explanation of a fascinating, relevant, and surprising anecdote. But it also represents what I like least: the lack of any threads to follow. I don’t really know anything about that Swedish study besides what Kean chose to tell in a couple of paragraphs. I looked through the book’s endnotes and bibliography, and even went to the additional notes found on the book’s web site. But I still don’t know the name of those Swedish researchers, the years covered in the study, the date they published their results, where the results were published, or anything else about it that might be relevant if I wanted to find out more or evaluate things for myself.
Call me old-fashioned, but I like to know the name and affiliation of a scientist whose work is being described, and the name of the book or article a particular cool factoid comes from. I like to be able to Google that scientist to find out what other work she’s done, or to track down that book hoping to find a topic for my own next writing project. And I like to be able to judge for myself, if I’m skeptical, whether the study was well-designed and sufficiently peer-reviewed.
This is not a small thing. Paul de Kruif sometimes got into trouble for writing in what his contemporaries described as “jazz style,” by which they meant that Microbe Hunters tended to be “truthy” rather than absolutely “true.” In the chapter on Louis Pasteur, for instance, de Kruif described the great bacteriologist awaiting the results of his experimental anthrax vaccine, which he had administered to dozens of sheep, goats, and cattle. “Pasteur rolled and tossed around in his bed and got up fifty times that night,” de Kruif wrote. Really? Fifty times? “He said absolutely nothing when Madame Pasteur tried to encourage him and told him, ‘Now now everything will come out all right.’” Really? Pasteur’s wife really said that? “[H]e sulked in and out of the laboratory,” de Kruif continued, “there is no record of it, but without a doubt he prayed.” At last, the admission that this particular detail, the one about prayer, is pure conjecture. It is one of dozens of similar conjectures de Kruif made, usually without remarking upon them, throughout the book.
Jazz style has its charms, of course. All those riffs on what scientists might have been doing and thinking are what made Microbe Hunters such a rollicking adventure. But when writers make their research seem casual and impromptu, it becomes crucial to cover their tracks with scrupulous citations. Lack of transparency can get a writer in trouble, and the more popular the writer the more he or she can become a target. Jonah Lehrer, for instance, was the author of the huge bestseller Imagine and a New Yorker staff writer when he got into hot water in June for reselling the same material to different publications, writing blog posts on the New Yorker website that were eerily similar to other posts and articles he had written just months earlier. (Most people referred to it by the inherently contradictory term self-plagiarism; one wag called it “me-cycling.”) To me, the question of whether Lehrer recycled the same material in articles or books was a matter between him and his editors, and might have been permissible if he had been clear with them—and clear with his readers—with a simple “as I wrote recently in Wired” and a link to his earlier work. Things finally exploded for Lehrer in July, when he was accused not only of “me-cycling” but of getting sloppy with his quotes. His accusers said that he implied that statements were made directly to him when they hadn’t been and, more egregiously, that he invented some quotes altogether. After Lehrer resigned from the New Yorker and his publisher took Imagine off the shelves, much debate ensued about whether Lehrer took these shortcuts because he was over-stretched, lazy, deliberately deceitful, or unaware of the basic tenets of journalism.
Kean leaves himself open to similar questions through a casual approach to citations. I don’t doubt that this book is meticulously researched and completely factual, but Kean gives me no way to know for sure—and no help in finding out more if I wanted to. At several passages in The Violinist’s Thumb, I found myself thinking about de Kruif and Microbe Hunters. “Mercifully, [King] Charles often ejaculated prematurely,” Kean writes, and I turned to the endnotes to see how he got that bizarre bit of information. But the endnotes were mum about this detail. And I was left, here and at too many times throughout the book, with the same thought I had about Louis Pasteur’s fretful tossing and turning: How does he know this?
Not only are the endnotes thin; so is the bibliography, with some fairly obvious sources left out. I can’t imagine how Kean managed to write his chapter about Barbara McClintock and her research on jumping genes, for instance, without reading A Feeling for the Organism by Evelyn Fox Keller. But Keller’s book is not mentioned in either the endnotes or the bibliography. The only source mentioned is Nathaniel Comfort, “the scholar most responsible for challenging the canonical version” of McClintock’s life story, with the citation of a single journal article from 1999. Just for the sake of thoroughness, it would have been nice to include a citation of the canonical version, too.
I understand that no one wants to clutter up a popular book with footnotes, or interrupt the prose with experts’ names and affiliations, or weigh down a hardcover with pages and pages of references. But there are ways to impart research without being ponderously academic. Using endnotes rather than footnotes is one way—which Kean does, though most of his endnotes consist not of references but of yet more anecdotes, which are too strange even for the main text, and also offered without citations. Kean is a master at web writing, having turned The Violinist’s Thumb into a Slate series called “Blogging the Human Genome,” just as he turned his previous book, The Disappearing Spoon, into a Slate series called “Blogging the Periodic Table.” Couldn’t he have exploited the web’s limitless opportunities for sourcing—linking to other articles and original scientific papers, for instance—by keeping his research for The Violinist’s Thumb online? He does this to some extent, but mostly just to tell additional stories, not to offer any informational leads.
I realize these complaints might seem churlish. But I think something serious is going on. The casual approach to citations and endnotes reflects a looser, bloggier approach to scholarship that diminishes the work. There’s no need to refer to someone as “a scientist” when that person has a name and Kean, no doubt, knows the name. In the age of Google, that name is particularly valuable. Without it, there’s no good way to dig deeper into Kean’s more colorful stories. It seems a missed opportunity not to offer us a way in.