Mapping the Human Gene
Less than 40 years ago James Watson and Francis Crick uncovered the secret of DNA and how it controls heredity, and everything that has been learned about it since has strengthened its position as the key to all life. Recently, medical science has discovered genes associated with a variety of human ailments, including manic depression, muscular dystrophy and Alzheimer’s disease, and all indications suggest that these discoveries are just the beginning.
But a full understanding of the DNA that makes up human genes is far from complete. Parts of genes have been studied and sequenced--to use the biologists’ term--but vast stretches of human genetics remain locked in mystery. Many biologists believe the time has come to remove the shroud and figure out the exact sequence of amino acids that make up human DNA. We agree.
This is a daunting task. It is believed that there are some 3 billion such amino acids--or bases--that make up the human genome, and vast stretches of them are apparently meaningless. In fact, no one is sure how the body distinguishes the meaningful segments of its genes from the gibberish. Even at the molecular level, it all looks the same. But the very fact that you are reading these words demonstrates that cells do distinguish the significant from the insignificant, or else you wouldn’t have eyes.
The present techniques for determining the sequence of parts of DNA are inefficient and expensive. A full-scale project to map the entire human genome, as it is called, would spur the development of new techniques and new equipment for doing it. The total project, which would cost $1 billion or more, would harness an entire generation of biologists, not just in the United States but around the world. But the payoff would be enormous. There are undoubtedly many more diseases that are genetically controlled and could be genetically attacked if only we knew which parts of which genes were involved.
Most of what biology has learned in this century has supported the view that human beings are just machines that walk around and talk to each other, but this is clearly too simple. Nurture plays a role in human development along with nature, though no one knows where one ends and the other begins. If we had a clearer idea of nature’s true role, we would also know better where free will takes over.
The Department of Energy has a small project under way on sequencing the human genome, and the National Academy of Sciences has a committee studying the issue and how it should be attacked. There is understandable concern in some quarters that yet another Big Science project funded by the federal government will take still more money away from the Little Science that has traditionally been the driving force of biology.
Unlike physicists, who have been accustomed to massive government endeavors since the Manhattan Project, biologists have done their work in small groups and small laboratories. A coordinated project to sequence the human genome should not be allowed to overwhelm that. But the importance of the task for knowledge and for human betterment cannot be overstated. DNA is the most important chemical of life, and understanding it fully is now within reach. An international effort to sequence the human genome may be one of the most important scientific activities of this century.
