The Violinist's Thumb: And Other Lost Tales of Love, War, and Genius, as Written by Our Genetic Code
Authors: Sam Kean
Copyright © 2012 by Sam Kean
Cover design by Will Staehle
Cover copyright © 2012 by Hachette Book Group, Inc.
All rights reserved. In accordance with the U.S. Copyright Act of 1976, the scanning, uploading, and electronic sharing of any part of this book without the permission of the publisher constitute unlawful piracy and theft of the author’s intellectual property. If you would like to use material from the book (other than for review purposes), prior written permission must be obtained by contacting the publisher at [email protected]. Thank you for your support of the author’s rights.
Little, Brown and Company
Hachette Book Group
237 Park Avenue, New York, NY 10017
First e-book edition: July 2012
Little, Brown and Company is a division of Hachette Book Group, Inc., and is celebrating its 175th anniversary in 2012. The Little, Brown name and logo are trademarks of Hachette Book Group, Inc.
The publisher is not responsible for websites (or their content) that are not owned by the publisher.
The Hachette Speakers Bureau provides a wide range of authors for speaking events. To find out more, go to
hachettespeakersbureau.com
or call (866) 376-6591.
Frontispiece illustration by Mariana Ruiz and László Németh.
ISBN 978-0-316-20297-8
ONTENTS
1. Genes, Freaks, DNA: How Do Living Things Pass Down Traits to Their Children?
2. The Near Death of Darwin: Why Did Geneticists Try to Kill Natural Selection?
3. Them’s the DNA Breaks: How Does Nature Read—and Misread—DNA?
4. The Musical Score of DNA: What Kinds of Information Does DNA Store?
M
AKING
T
HINGS
T
HAT
C
RAWL AND
F
ROLIC AND
K
ILL
5. DNA Vindication: Why Did Life Evolve So Slowly—Then Explode in Complexity?
6. The Survivors, the Livers: What’s Our Most Ancient and Important DNA?
7. The Machiavelli Microbe: How Much Human DNA Is Actually Human?
8. Love and Atavisms: What Genes Make Mammals Mammals?
9. Humanzees and Other Near Misses: When Did Humans Break Away from Monkeys, and Why?
10. Scarlet A’s, C’s, G’s, and T’s: Why Did Humans Almost Go Extinct?
11. Size Matters: How Did Humans Get Such Grotesquely Large Brains?
12. The Art of the Gene: How Deep in Our DNA Is Artistic Genius?
G
ENETICS IN THE
P
AST
, P
RESENT, AND
F
UTURE
13. The Past Is Prologue—Sometimes: What Can (and Can’t) Genes Teach Us About Historical Heroes?
14. Three Billion Little Pieces: Why Don’t Humans Have More Genes Than Other Species?
15. Easy Come, Easy Go? How Come Identical Twins Aren’t Identical?
16. Life as We Do (and Don’t) Know It: What the Heck Will Happen Now?
Epilogue: Genomics Gets Personal
In accordance with the U.S. Copyright Act of 1976, the scanning, uploading, and electronic sharing of any part of this book without the permission of the publisher constitute unlawful piracy and theft of the author’s intellectual property. If you would like to use material from the book (other than for review purposes), prior written permission must be obtained by contacting the publisher at [email protected]. Thank you for your support of the author’s rights.
Life, therefore, may be considered a DNA chain reaction.
—M
AXIM
D. F
RANK
-K
AMENETSKII
,
U
NRAVELING
DNA
Acrostic:
n., an incognito message formed by stringing together the initial letters of lines or paragraphs or other units of composition in a work.
N.B.: I’ve hidden a DNA-related acrostic in
The Violinist’s Thumb—
a genetic “Easter egg,” if you will. If you decode this message, e-mail me through my website (
http://samkean.com/contact
). Or if you can’t figure it out, e-mail me anyway and I’ll reveal the answer.
T
his 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. And yes, I’m writing this book despite the fact that my father’s name is Gene. As is my mother’s name. Gene and Jean. Gene and Jean Kean. Beyond being singsong absurd, my parents’ names led to a lot of playground jabs over the years: my every fault and foible was traced to “my genes,” and when I did something idiotic, people smirked that “my genes made me do it.” That my parents’ passing on their genes necessarily involved sex didn’t help. The taunts were doubly barbed, utterly unanswerable.
Bottom line is, I dreaded learning about DNA and genes in science classes growing up because I knew some witticism would be coming within about two seconds of the teacher turning her back. And if it wasn’t coming, some wiseacre was
thinking
it. Some of that Pavlovian trepidation always stayed with me, even when (or especially when) I began to grasp how potent a substance DNA is. I got over the gibes by high school, but the word
gene
still evoked a lot of simultaneous responses, some agreeable, some not.
On the one hand, DNA excites me. There’s no bolder topic in science than genetics, no field that promises to push science
forward to the same degree. I don’t mean just the common (and commonly overblown) promises of medical cures, either. DNA has revitalized every field in biology and remade the very study of human beings. At the same time, whenever someone starts digging into our basic human biology, we resist the intrusion—we don’t want to be reduced to mere DNA. And when someone talks about tinkering with that basic biology, it can be downright frightening.
More ambiguously, DNA offers a powerful tool for rooting through our past: biology has become history by other means. Even in the past decade or so, genetics has opened up a whole Bible’s worth of stories whose plotlines we assumed had vanished—either too much time had lapsed, or too little fossil or anthropological evidence remained to piece together a coherent narrative. It turns out we were carrying those stories with us the entire time, trillions of faithfully recorded texts that the little monks in our cells transcribed every hour of every day of our DNA dark age, waiting for us to get up to speed on the language. These stories include the grand sagas of where we came from and how we evolved from primordial muck into the most dominant species the planet has known. But the stories come home in surprisingly individual ways, too.
If I could have had one mulligan in school (besides a chance to make up safer names for my parents), I’d have picked a different instrument to play in band. It wasn’t because I was the only boy clarinetist in the fourth, fifth, sixth, seventh, eighth, and ninth grades (or not only because of that). It was more because I felt so clumsy working all the valves and levers and blowholes on the clarinet. Nothing to do with a lack of practice, surely. I blamed the deficit on my double-jointed fingers and splayed hitchhiker thumbs. Playing the clarinet wound my fingers into such awkward braids that I constantly felt a need to crack my knuckles, and they’d throb a little. Every blue moon one thumb
would even get stuck in place, frozen in extension, and I had to work the joint free with my other hand. My fingers just didn’t do what the better girl clarinetists’ could. My problems were inherited, I told myself, a legacy of my parents’ gene stock.
After quitting band, I had no reason to reflect on my theory about manual dexterity and musical ability until a decade later, when I learned the story of violinist Niccolò Paganini, a man so gifted he had to shake off rumors his whole life that he’d sold his soul to Satan for his talent. (His hometown church even refused to bury his body for decades after his death.) It turns out Paganini had made a pact with a subtler master, his DNA. Paganini almost certainly had a genetic disorder that gave him freakishly flexible fingers. His connective tissues were so rubbery that he could pull his pinky out sideways to form a right angle to the rest of his hand. (Try this.) He could also stretch his hands abnormally wide, an incomparable advantage when playing the violin. My simple hypothesis about people “being born” to play (or not play) certain instruments seemed justified. I should have quit when ahead. I kept investigating and found out that Paganini’s syndrome probably caused serious health problems, as joint pain, poor vision, weakness of breath, and fatigue dogged the violinist his whole life. I whimpered about stiff knuckles during early a.m. marching-band practice, but Paganini frequently had to cancel shows at the height of his career and couldn’t perform in public during the last years of his life. In Paganini, a passion for music had united with a body perfectly tuned to take advantage of its flaws, possibly the greatest fate a human could hope for. Those flaws then hastened his death. Paganini may not have chosen his pact with his genes, but he was in one, like all of us, and the pact both made and unmade him.