Connecting the dots in DNA book

June 30, 2000|By Ellen Goodman

WASHINGTON -- They all talked about it as a book, although e-book is a better analogy. If the human genome were actually printed out on paper it would rise as high as the Washington Monument.

On Monday, to enormous fanfare, competing scientists from Celera Genomics Corp. and the federal Human Genome Project jointly announced the publication of the "Book of Life." For the first time, we have a working draft of the instruction manual for making and growing a human being. And though it isn't exactly a beach book, it is a blockbuster.

Using only four chemical letters -- G, A, T, C -- this book of life promises to affect the way we think about ourselves as much as any scientific achievement in human history. If Galileo pushed us out of the center of the universe, if Newton gave regularity to a world ruled by whim and gods, if Darwin gave us our origins, the human genome alters our identity in conflicting new ways.

The mapping of a human genetic code tells that we share a single blueprint. We are genetically a small band of descendents of the same people. We are 99.9 percent the same as each other.

Yet as we build a catalog of human variation from these letters we also learn the ways in which each of us is genetically different, wholly individual. We share the book, but have a page, or maybe a sentence, of our own.

The theme of this work is that humans are simultaneously alike and unique.

"It's a paradox," says Francis Collins, the head of the Human Genome Project, sitting quietly after the hubbub of the White House announcement. "What genes teach us is that we are incredibly alike and yet also they give us a concrete way of knowing how different we are."

Eric Lander, from the Whitehead Institute, a crucial partner in this project, uses a different literary analogy to explain the shared book of life. "It's like a family Bible that's been passed down the generations. There are little spelling differences, small punctuation differences, but it's the same Bible. The genome reminds us how close we are."

There is, he says, "so much to unite us. Our ancestors left so many stories in the DNA." We'll be able to tell if we share an ancestor 50,000 years ago. Indeed we'll be able to tell how much we share with the rest of nature, from yeast to a mouse.

But at the same time, Mr. Lander too wonders to what extent the genetic codes we are beginning to catalog will divide us in new and unsettling ways.

With gene testing, with diagnostic testing, we may well be able to predict illness, to tailor drugs, even to alter genetic make-up. Along with the stunning possibilities for truly individualized treatment for disease also come the sober possibilities for a new kind of splintering.

"We have now 3 million ways to subdivide people and one way to unite everyone," he says, "We will need an appreciation of diversity that we've not had."

The human genome debunks any scientific concept of "race." We will find out that there is more variation within a racial or ethnic group than between groups. But will it usher in a kind of molecular discrimination? We may also begin to redraw lines so that a person once grouped as, say, Italian-American, ends up grouped as pre-Alzheimer's, or high-risk breast cancer.

This is why a publication day filled with toasts to what President Clinton described as a "stunning, humbling achievement" was also filled with warnings. The two "team leaders," J. Craig Venter of Celera and Mr. Collins of the Genome Project, men who have disagreed on much, seconded each other in warning about genetic discrimination.

At the everyday level, we clearly need to extend the prohibition against genetic discrimination.

But at a deeper level, as Mr. Lander says, we need to stretch our minds as far as the lengthy curve of DNA. "The whole notion of differences between us has been about ranking people," he says. "We need to get that out of our heads." Difference has been a way to describe who's up and who's down, who's in and out. Using another analogy from another Good Book, Mr. Collins adds, "We are all fallen creatures at the DNA level."

So we enter a new age. We can see, literally, in the DNA, how we are connected through human history and separated by our own individuality. But there is no gene that can predict the human sequel. We have the book, but how will we read it?

Ellen Goodman is a columnist with the Boston Globe and her e-mail address is

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