The Genius in All of Us: New Insights Into Genetics, Talent, and IQ (21 page)

Newer “Peloria” toadflax

Courtesy of Emil Nilsson

Ordinary toadflax

Courtesy of Emil Nilsson

The trouble was, this difference couldn’t be found on the genes. When they looked closely at the gene known to be associated with flower symmetry, a gene known as
Lcyc
, Coen’s team was astounded to find that the DNA code in each plant was exactly the same. Two very distinct flowers, same genetic code.

What they discovered next was even more surprising.
There
was
a difference between the two flowers on their respective
epigenomes
—the packaging that surrounds DNA.

Some quick background on genetic architecture:
DNA is famously wound together in a double-helix strand
that, close-up (at a magnification of about 10 million times), looks like this:

From farther away, those same DNA strands look much smaller, of course, and one can see that each strand is coiled around a protective packaging of histone proteins, which (at a magnification of about 1 million times) looks like this:

Courtesy of Hadel Studio

These histones protect the DNA and keep it compact
. They also serve as a mediator for gene expression, telling genes when to turn on and off. It’s been known for many years that this epigenome (“epi-” is a Latin prefix for “above” or “outside”) can be altered by the environment and is therefore an important mechanism for gene-environment interaction.

What scientists didn’t realize, though, was that changes to the epigenome can be inherited. Prior to 1999, everyone thought that the epigenome was always wiped clean like a blackboard with each new generation.

Not so, discovered Enrico Coen. In the case of the Peloria toadflax flower, a clear alteration to the epigenome had subsequently been passed down through many generations.

And it wasn’t just flowers. That same year, Australian geneticists Daniel Morgan and Emma Whitelaw made a very similar discovery in mice.
They observed that their batch of genetically identical mice were turning up with a range of different fur colors
—differences traced back to epigenetic alterations and passed on to subsequent generations. What’s more, they and other researchers discovered that these fur-color epigenes could be manipulated by something as basic as food.
A pregnant yellow mouse eating a diet rich in folic acid or soy milk would be prone to experience an epigenetic mutation producing brown-fur offspring, and even with the pups returning to a normal diet, that brown fur would be passed to future generations
.

After that, more epigenetic discoveries piled in one after another:

• In 2004, Washington State University’s Michael Skinner discovered that
  exposure to a pesticide in one generation of rats spurred an epigenetic change
  that led to low sperm counts lasting at least four generations.
  

• In 2005, New York University’s Dolores Malaspina and colleagues discovered
  age-related epigenetic changes in human males
  that can lead to lower intelligence and a higher risk of schizophrenia in children.
  

• In 2006, London geneticist Marcus Pembrey presented data from Swedish medical records to show that
  nutritional deficiencies and cigarette smoking in one generation of humans had effects across several generations
  .
  

• In 2007, the Institute of Child Health’s Megan Hitchins and colleagues reported a
  link between inherited epigenetic changes and human colon cancer
  .
  

Welcome back, Monsieur Lamarck!
“Epigenetics is proving we have some responsibility for the integrity of our genome,” says the Director of Epigenetics and Imprinting at Duke University, Randy Jirtle
. “Before, [we thought that] genes predetermined outcomes. Now [we realize that] everything we do—everything we eat or smoke—can affect our gene expression and that of future generations. Epigenetics introduces the concept of free will into our idea of genetics.”

And that of future generations
. This is big, big stuff—perhaps the most important discovery in the science of heredity since the gene.

No one can yet measure the precise implications of these discoveries, because so little is known. But it is already clear that epigenetics is going to radically alter our understanding of disease, human abilities, and evolution. It begins with this simple but utterly breathtaking concept:

Lifestyle
can
alter heredity
.

Lamarck was probably not correct about the giraffe in particular, and he was certainly wrong about inherited characteristics being the primary vehicle of evolution. But in its most basic form, his idea that what an individual does in his/her life before having children can change the biological inheritance of those children and their descendants—on this he turns out to have been correct. (And two hundred years ahead of everyone else.) Quietly, biologists have come to accept in recent years that biological heredity and evolution is a lot more intricate than we once thought. The concept of inherited epigenetic changes certainly does not invalidate the theory of natural selection, but it makes it a lot more complicated. It offers not just another mechanism by which species can adapt to changing environments, but also the prospect of an evolutionary process that is more interactive, less random, and runs along several different parallel tracks at the same time. “DNA is not the be all and end all of heredity,” write geneticists Eva Jablonka and Marion Lamb.
“Information is transferred from one generation to the next by many interacting inheritance systems
. Moreover, contrary to current dogma, the variation on which natural selection acts is not always random … new heritable variation can arise in response to the conditions of life.”

How do these recent findings impact our understanding of talent and intelligence? We can’t yet exactly be sure. But the door of possibility is wide-open. If a geneticist had suggested as recently as the 1990s that a twelve-year-old kid could improve the intellectual nimbleness of his or her future children by studying harder now, that scientist would have been laughed right out of the conference hall. Today, that preposterous scenario looks downright likely:

Washington, D.C.—
New animal research in the February 4 [2009] issue of
The Journal of Neuroscience
shows that a stimulating environment improved the memory of young mice with a memory-impairing genetic defect and also improved the memory of their eventual offspring
. The findings suggest that
parental behaviors that occur long before pregnancy may influence an offspring’s well-being
. “While it has been shown in humans and in animal models that enriched experience can enhance brain function and plasticity, this study is a step forward, suggesting that the enhanced learning behavior and plasticity can be transmitted to offspring long before the
pregnancy of the mother,” said Li-Huei Tsai, PhD, at Massachusetts Institute of Technology and an investigator of the Howard Hughes Medical Institute, an expert unaffiliated with the current study.

In other words, we may well be able to improve the conditions for our grandchildren by putting our young children through intellectual calisthenics now.

What else is possible? Could a family’s dedication to athletics in one or more generations induce biological advantages in subsequent generations?

Could a teenager’s musical training improve the “musical ear” of his great-grandchildren?

Could our individual actions be affecting evolution in all sorts of unseen ways?

“People used to think that once your epigenetic code was laid down in early development, that was it for life,” says McGill University epigenetics pioneer Moshe Szyf
. “But life is changing all the time, and the epigenetic code that controls your DNA is turning out to be the mechanism through which we change along with it. Epigenetics tells us that little things in life can have an effect of great magnitude.”

Everything we know about epigenetics so far fits perfectly with the dynamic systems model of human ability. Genes do not dictate what we are to become, but instead are actors in a dynamic process. Genetic expression is modulated by outside forces. “Inheritance” comes in many different forms: we inherit stable genes, but also alterable epigenes; we inherit languages, ideas, attitudes, but can also change them. We inherit an ecosystem, but can also change it.

Everything shapes us and everything can be shaped by us. The genius in all of us is our built-in ability to improve ourselves and our world.

Join other readers in online discussion of this chapter: go to
http://GeniusTalkCh10.davidshenk.com

Epilogue
Ted Williams Field

P
arts of the North Park neighborhood of San Diego don’t seem to have changed a whole lot since Ted Williams’s time.
His tiny boyhood home at 4121 Utah Street still stands
.
Two short blocks away, his old practice baseball field is still there too
. They call it “Ted Williams Field” now. Outside the batting cage are sign-up sheets for Little League. On the sunny afternoon I was there, the field sat empty; no one feverishly hitting baseballs until the threads and skins wore off, no one shagging balls for lunch money. Maybe instead some eleven-year-old kid was inside somewhere practicing the cello with all his heart or building a new piece of software that will change the world.

With the field completely empty, it was easier to imagine Ted standing at home plate, yelling at his friend to throw another one—
and harder this time;
to see a few kids standing in the outfield, gloveless, trying to catch the balls but missing most of them. The bat cracks every few seconds, and Ted occasionally mutters,
“That’s it, that’s it.”
Every time he misses the ball or cracks a foul, he takes note of his stance and his swing. He marks how the ball left the pitcher’s hand, how it spun and how it traveled, when he started his swing, and exactly how he moved his shoulders and his hips and his wrists.