Reading the human Rosetta stone. Scientists are on the verge of a multimillion-dollar attempt to decipher the genetic information of human beings.
BIOLOGISTS have broken the genetic code. They've read some of the instructions that determine the composition of simple organisms. They've altered a few plants and bacteria. Now some of them are after a far bigger prize - the human genome. The genome is the entire 3 billion-letter ``text'' that contains the genetic instructions for the formation of human beings. That's roughly the number of letters in three year's run of a major seven-day-a-week metropolitan newspaper. So far, the longest such ``text'' the biologists have read is the 172,000-letter sequence of the Epstein-Barr virus - less than 10 percent of a single newspaper issue, using the analogy above. An intensive, dedicated project to go from that to getting the complete sequence of the human genome's 3 billion letters would be the most ambitious single effort biologists have ever undertaken.
Cost estimates run between several hundred million and $1 billion. It probably would take 10 to 20 years to complete. This would catapult biologists - who are used to working in small groups on small programs - into the realm of ``big science.'' It would be for them what building a particle accelerator is for physicists or orbiting the Hubble space telescope is for astronomers - a prospect some biologists view with trepidation.
As momentum builds toward organizing such a project, there is sharp debate among biologists about the wisdom for rushing ahead.
For Walter Gilbert of Harvard University, a dedicated effort to sequence the human genome would be ``like pursuing the Holy Grail.'' The Nobel Prize winning microbiologist says it would create the biological equivalent of the Rosetta stone - ``a complete library of information that biologists could search'' to find the genetic instructions for making a human being. It would be a major aid in understanding gene-linked diseases and developing medical treatments for them. It also should aid in developing many new drugs based directly on chemicals the body uses naturally.