It was RAFI that led the charge against the patenting of the Hagahai's cell line in 1995. The tiny organization, with a staff of about a half-dozen, has gone on to earn the wrath of academics and industrial geneticists for its David-and-Goliath campaign against diversity research.

According to RAFI and a shifting coalition of other indigenous groups, the expanding hunt for cures locked within the nuclei of the isolated peoples is an unsavory replay of an earlier genetic safari to the Third World.

In the 1970s, big agribusiness firms raided equatorial countries for lucrative crop hybrids that, with a bit of genetic engineering, later earned billions in profits--cash that rarely trickled back to the impoverished farmers who raised the strains initially, Hammond said.

"Today," he said, "the crop is human beings."

Declarations such as these have sent alarm bells ringing around the world, especially in the ethnically diverse nations of Asia. India, which launched its human-diversity project this year, takes the threat of "bioprospecting" seriously enough to declare its citizens' DNA a national treasure. Blood samples can't leave the country.

Meanwhile, RAFI's bioengineering crusade marches on, pushing for a ban on the patenting of human DNA, demanding that companies share profits with the populations who offer their genes for commercial research and lobbying the United Nations to regulate the burgeoning "human-tissue trade."

Medical-industry spokesmen dismiss such demands as wishful thinking. Without patents on DNA, they say, few businesses would invest in the research necessary to develop genetic cures.

"Do I have some theological objection to individuals participating in and benefiting from the economic upside of such research? No," said Kevin Kinsella, president of Sequana Therapies. "But the picture is far more complex than that. Gene discovery is just the first step in a 1,000-mile journey to find a therapy. It's a process that costs us millions and takes years of work. So how much does somebody who gets his arm pricked deserve?"

Kinsella noted angrily that the Tristan da Cunha islanders who are participating in his company's asthma studies are not "natives running around in grass skirts" but the descendants of British colonists. In exchange for the islanders' blood, he said, his company has promised to give back free drugs developed from the research.

Still, even those scientists who are most enthralled by the wondrous medicine cabinet opened by the foibles of human genetic variation say that serious moral questions will take years.

When a researcher walks tired and dusty into a village with his bag of syringes, who does he ask for permission to collect a population's DNA? The individual donor? The group's religious or political leader? Who owns a peoples'--not a person's--DNA?

And, more important, how can scientists possibly obtain informed consent--as is required by most governments--when they can't explain the profound repercussions of genetic testing to preliterate cultures?

"These are untested waters," said Dunston, the diversity project planner. "Scientists have to start by learning to treat people like people, not scientific subjects. After all, this whole exploration is about sharing what makes us human--scientists are truly part of the experiment in this case."

Dunston described one of the more serendipitous discoveries of diversity research that convinced her of its ultimate righteousness:

In seeking organ donors for African-Americans, doctors have found that in some cases tissue from whites is a closer match than tissue from other African-Americans.

The reason? African populations are so ancient that they have diverged into the most genetically variable peoples. Hence, the differences between two African-Americans could be greater than those between a white and an African-American, vivid proof that skin color can mask DNA affinities.

"It would be a shame to lose such insights to fears about commercialization of DNA," she said, worrying aloud that the diversity project, whose aim is pure science, is being sullied by the profit-driven motives of pharmaceutical companies. "This is medicine helping tear down old ways of thinking about race."

But some, especially those caught in the middle of the gene hunters, remain deeply ambivalent.

For Pennsylvania's Amish community, whose religious strictures against outmarriage have kept their gene pool unclouded for almost three centuries, the issue boils down to accountability and respect for the sense of ownership kindled by DNA.

"They came, they took blood, they made promises and they never reappeared," said Rebecca Huyard, a medical administrator in Strasburg, Pa., who remembers how disease researchers from Johns Hopkins University collected hundreds of genetic samples among the farming folk of Lancaster County in the 1970s and 1980s.

"Eventually, people here got fed up with it. They wondered where their blood was going. It was, after all, our blood, our DNA."

Huyard, who is Amish, said she and her devout, buggy-riding neighbors fear that their molecular inheritance--the building blocks of their biological identity--has somehow slipped beyond their control. She hoped that Amish DNA samples weren't being shared without the donors' knowledge. She also bemoaned the lack of awareness about a momentous scientific quest that, however noble, is speeding ahead almost without public debate.

"Now, we don't trust any of them anymore," Huyard said. She added that if diversity researchers showed up again in the silo-studded hills of Amish country, they probably would be turned away politely but firmly at farm doors.

What she didn't know was that several biotech firms have acquired Amish DNA and are interrogating it for clues to everything from Alzheimer's disease to diabetes. That Amish DNA, frozen and cultured in petri dishes, sits alongside thousands of other human cell lines in laboratories and refrigerators around the world.