Thumbthing Worth Reading

I intended to read Sam Kean’s new book The Violinist’s Thumb: And Other Lost Tales of Love, War, and Genius as Written by our Genetic Code  just for fun. I was expecting a miscellany of trivia loosely gathered around the theme of DNA. But I found something much more worthwhile that I thought merited a book review to bring it to the attention of our readers. Kean interweaves entertaining stories into a somewhat disjointed but nonetheless valuable history and primer of genetics. The title refers to Paganini, whose DNA created the unusual joint flexibility that facilitated his unprecedented feats of virtuosity on the violin.

Kean details the discovery of genes, chromosomes, and DNA; not only with the well-known players (Mendel, Watson, Crick) but with more obscure researchers, weird fruit fly studies, womanizers, scientists who fought against the growing consensus, those who unraveled the complexities of how our cells read the genetic code, those who took some very wrong turns, and the complex politics that plagued the human genome project. His vignettes make the scientists come alive.

Along with the basics about inheritance and the G-T-A-C code, we learn about endosymbiosis, the incorporation of viral DNA into the human genome, jumping genes, viral DNA manipulation of host behavior, the complications introduced by the development of the X and Y chromosomes, how a person’s environment can alter the expression of genes in their children and even their grandchildren (epigenetics), gene reassortment, how genes are read and mis-read, how DNA ties itself in knots that have to be unraveled by canny proteins called topoisomerases, why identical twins are not truly identical, why we have fewer chromosomes than any other primate, how the box gene organizes development in the embryo, and how “junk” DNA is proving to be anything but.

Along the way, we learn about a couple who shared their house with 689 cats, an oddball piece of math (Zipf’s law) that applies to both linguistics and DNA coding, an unlucky man who fled Hiroshima after the bombing only to be bombed again in Nagasaki, explorers who died of vitamin A poisoning from eating polar bear liver because humans lack the genes that polar bears have evolved to protect themselves, a Russian scientist who tried to create a human/chimp hybrid by inseminating women with chimp sperm either with or without their consent, the postmortem peregrinations of Einstein’s brain tissue, the origin of funny names for genes like sonic hedgehog, and Darwin’s mysterious lifelong health problems.

We learn how DNA illuminates human history and evolution. The rate of mutation is steady enough to serve as a clock. In a bottleneck after the eruption of a monster volcano, the population of humans dropped precipitously, perhaps even as low as 40 adults. Because of that, we have far less genetic diversity than chimps and gorillas, even though our current population is 7 billion and theirs is only 150,000.

Gene sequencing is getting cheaper every day. We can only speculate what the future may bring. We may eventually have the technology to eliminate genetic defects in individuals and to direct the evolution of our species.

Kean’s colorful cast of characters is unending. We meet Craig Venter, the midwife toad, Stalin, Dolly the sheep, Toulouse-Lautrec, Neanderthal cannibals, a Cyclops, King Tut, and Kim Peek, the inspiration for “Rain Man” whose abnormal brain could perform astounding feats of reading and memory but couldn’t handle simple tasks of daily living. We meet a Victorian zoophagy enthusiast who thought moles were the worst-tasting animal until he ate a bluebottle fly.

A Lesson About Personal Genomic Testing

I was particularly interested in Kean’s experience with testing his own DNA because it illustrated some of the concerns that both Scott Gavura and I have raised.

When his results were reported, the company gave him the option to not learn his risk of specific diseases. He opted not to know his risk of Parkinson’s, a disease he particularly dreaded because he had bad memories of his grandfather’s deterioration from it. When he read about Craig Venter publishing everything about his genome, he was inspired by that example to unseal his own results. He was relieved to learn he had no increased risk for Parkinson’s after all. His emotional relief was only minimally impacted by his rational understanding that “no increased risk” didn’t mean “no chance” of getting Parkinson’s. Later the company announced updates to the old results based on new scientific studies. A new study had looked at the DNA in a different spot on the genome and it showed he had a slightly greater than average risk of developing Parkinson’s. He felt as if he had been condemned, pardoned, and then condemned again.

His reaction was tempered by what he had learned during research for this book:

  • Parkinson’s is complex, affected by many genes.
  • Any one gene probably contributes very little.
  • Slightly higher was defined as just 20%.
  • Parkinson’s only affects 1.6% of men. (If the baseline risk is 1.6% and his risk is 20% higher, that would only raise it to 1.92%.)
  • The new study was classified by the company as “preliminary.”
  • Preliminary results are subject to amendments and reversals.

In short, genetic testing shows probabilities, not certainties. It seldom leads to useful preventive actions and it can lead to unnecessary anxiety or false reassurance for those who don’t know enough about genetics to appreciate the limitations of the findings. Scott Gavura said it well:

Our access to genetic information currently exceeds our understanding of what that information actually means.


Thumbs up to The Violinist’s Thumb. You will learn things you didn’t know and you will be heartily entertained in the process.


Posted in: Basic Science, Book & movie reviews, Evolution, History

Leave a Comment (20) ↓

20 thoughts on “Thumbthing Worth Reading

  1. windriven says:

    Amazon thanks you! For those who own e-readers, The Violinist’s Thumb is $12.99.

    “Our access to genetic information currently exceeds our understanding of what that information actually means.”

    One might argue that having that access will inevitably contribute to our eventual understanding.

  2. Artur Krol says:

    So are music academy students now all in possession of this same kind of gene Paganini had? Because what was virtuosity in his time is now standard fare for 2nd-3rd year violin students according to several university music teachers I’ve discussed the topic with.

    Research-wise, the genetic predisposition to mastery hypothesis just cannot be sustained at this point, unlike Ericsson’s “Deliberate Practice” mastery hypothesis. Which makes a lot of sense, when you come to think about it – the amount of effort, both cognitive and just pure time-based, required to become an expert is so large, that expertise couldn’t have had any serious influence of the natural selection during the time humanity was evolving. And while genetic makeup can influence the “novice level” effectiveness in various fields, the sheer time and effort needed to become an expert* makes the genetic advantage meaningless before reaching mastery. Now genetic disadvantage – like serious retardation – might obviously play a role, but we generally consider the possibility of a healthy person to become an expert.

    Genetics and heredity are fascinating subjects, but we must be careful to stick with quality research, and this research just does not support the inborn mastery potential hypothesis the Paganini anecdote suggests.

    *10.000 hours for most fields, but more for some, medicine was 12.000 hours of deliberate practice, for example

  3. Harriet Hall says:

    The book does not argue that Paganini had a genetic predisposition to mastery. It only argues that Paganini’s genes produced an unusual degree of flexibility in his thumb joint that increased his reach and facilitated his accomplishments. He was “double-jointed” (loose ligaments) and probably had Marfan’s syndrome. Rachmaninoff did too, and was able to play C–E-flat–G–C–G on the piano with his left hand. Some pianists are physically unable to play certain of his compositions.

  4. windriven says:

    For another take on Rachmaninoff’s incredible spread check this:

  5. gippgig says:

    Should “box gene” be “hox genes”?

  6. Kultakutri says:

    windriven, thanks for the link, I needed the good laugh.

  7. mousethatroared says:

    windriven – I’m sorry to ‘me too’ but that video is hilarious. Thanks

  8. windriven says:

    @Kultakutri and mouse

    I stumbled over that looking for a serious performance of the Rach 3. Pure serendipity. :-)

  9. Janet says:


    I loved it! Brilliant–and serendipitous indeed. I hear the music from Twilight Zone.


    Thanks for passing this on. I love books like this, light-ish but worthwhile reading. I have “double jointed” thumbs which sadly, I never used to any purpose other than to amaze and kind of gross out my friends. (I can twist my thumbs all the way behind my knuckles and more.)

  10. Janet says:

    Oh! I wanted to mention that I am on my way to LaCrosse, WI, to hear Brian Deer speak. ORAC posted it on his blog in case anyone hasn’t heard. As I’m in Wisconsin, I hitched the trailer up and headed out. I’ve stopped in Madison to see the grandkids, but will be there early on Thursday because….can you guess? Andrew Wakefield is going to make an appearance as well–a “press conference” apparently. Should be interesting.

  11. Chris says:

    Dr. Hall:

    The book does not argue that Paganini had a genetic predisposition to mastery.

    Le sigh. This is only a third hand account from daughter’s violin teacher. But the Paganini lore includes him being a showman. He apparently would break strings on the violin for a dramatic effect and then continue on! Especially long fingers could get him pressing a string very close to the bridge to create the high notes on another string of the missing E string (one that I often replaced on that violin… it is very thin).

    There is some genetics with hand size and finger strength with certain stringed instruments (and that actually includes piano, which with the hammers hitting the strings is a percussion instrument). And sometimes it has to do with age. When my younger son was eight years old his piano teacher helped him re-write some Star Wars music he wanted to play that included chords that exceeded his hand width (and yes, he could probably do them now as a college student if he wished, but work and school take up most of his time).

  12. BillyJoe says:

    Are the hands of all piano players spidery.
    My wife’s hands could send shivers up your spine.

  13. mousethatroared says:

    BillyJoe – what is spidery?

  14. windriven says:


    Fingers that are unusually long in comparison to the palm.

  15. Harriet Hall says:


    “Should “box gene” be “hox genes”

    homeobox genes:

  16. mousethatroared says:

    Windriven – oh, so the exact opposite of my hands. :( no piano playing for me.

  17. mousethatroared says:

    “Thumbs up to The Violinist’s Thumb.”. Hehe, some puns are so obvious, but still so gratifying. :)

    I’m going to check out this book. I’ve been looking for a way to learn about genetics, but haven’t found a presentation I found appealing enough for “entertainment” reading.

    In terms of genetics predisposition for mastery, I wonder. I don’t know if it’s confirmation bias or true, but within artist circles (my friends/previous coworkers) the high number of left handed people is often observed. But then I don’t know if that’s genetic.

    Sometimes it is the thing that makes a person different that lends itself to intriguing work. I went to school with a painter who had a color vision deficiet. He did these figurative expressionist pieces with an emphasis on value (black/white) and color schemes that were just jarring enough to be engaging. Likewise I also admire the work of an assemblage artist who has significant eyesight lose due to a genetic condition (I think) She uses photographs with a variation of focus that would probably not occur to a person with good vision.

    Sorry, I guess I wandered off-topic, but it’s interesting to think sometimes, about how what we are not makes us what we are.

  18. mousethatroared says:

    Warning Off-Topic

    Hey BillyJoe – I’m in the process of switching to my art brain, which often isn’t too focused on reading or commenting on SBM. I know you are only around intermittently. In case you are gone when I stick my head in again, I wanted to say how much I’ve enjoyed our chats. They help me clarify my thoughts on different issues.
    Cheers, MTR

  19. Artur Krol says:

    @Harriet – thanks for clarifying :)

    @Mousethatroared – try Coursera, I think they either already have courses in genetics, or will have shortly. They’re free and a lot of their courses are just brilliant.

  20. DugganSC says:

    I’m very much enjoying this one. I hadn’t realized just how seedy early genetics was…

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