“The realization came upon us that we were getting worse,” Thomas said, “and they were publishing studies and pamphlets. We said, ‘Hey, where’s the benefit?’ We have been used as a natural laboratory. They want to keep us under the microscope for as long as possible.”
Three generations of a Zuni family are participants in a diet and exercise program designed to fight diabetes. From left: Dora Weeka, Eloise Westika, and advertisement | article continues below
Carvella Weeka. |
Across the Indian Country of the West the collective feelings about genetic research are not hard to discern. The Navajo—at almost 300,000, the largest tribal population—have ruled out all participation in genetic studies. The Northern Plains tribes, which are mainly Sioux, have devised stiff protections and protocols many pages long. Researchers making proposals are required to state how the Indians could be harmed by the DNA findings as well as helped.
Last year the tiny Havasupai tribe of northern Arizona filed a $50 million lawsuit against Arizona State University and its scientists over a long-term project that looked for genes contributing to diabetes. The Indians claim that their consent was abused, their blood samples were mishandled, and that sacred information was written up without their approval. Almost as an aside, the lawsuit points out that no diabetes genes were revealed. The researchers have denied the legal charges.
The climate isn’t totally hostile. The Salt River Pima-Maricopa Indian Community, on the eastern edge of Phoenix, is talking with a company called Translational Genomics about possible research into the tribe’s ills. At the Zuni Pueblo reservation in western New Mexico, where I was headed after Gila River, the tribal council has cautiously opened the door to medical geneticists. And a long-running National Institutes of Health study called Strong Heart, which explores cardiovascular disease in Native Americans, has added a genetic component, so far without controversy.
Jacob Moore, an Indian who manages legislative affairs for the Salt River tribe, gave me a blunt explanation for the wariness: “Tribes in general have been taken advantage of for so long that there’s distrust. The attitude is, ‘The mainstream society has taken everything else. Once they have our genetic code, there isn’t anything left they can take from us.’ ”
By genetic code Moore did not mean the DNA that all people share. He was referring to a core identity that is, though he didn’t say so, both cultural and biological. On both fronts Indians are being threatened by assimilation. While maintaining their tribal affiliations, most Native Americans do not live on reservations. They intermarry with other ethnic groups; already their DNA shows substantial European American heritage. This exchange between population groups can be tracked through distinctive sets of genetic markers that provide clues to a person’s ancestry.
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The bottom line: All human beings inherit the same set of genes, but the various chemical spellings of our genes bear some relation to the geographic origins of our forebears. So when geneticists dispute the biological notion of “race,” with its false implication that certain genes pertain to certain races, they also recognize that DNA analysis can shed light on ancestry.
Not surprisingly, a scientist who studies markers for clues to ancestral origin is not a welcome figure in Indian Country. The tests might call into question who is an Indian—a question with psychological pitfalls and also financial consequences for one claiming benefits, say, from the tribe’s investments. Robert Williams, the anthropological geneticist at Arizona State University, collided with the question in a study for the Strong Heart cardiovascular project. His analysis of 12 tribal groups was abruptly halted after he found that the amount of European heritage varied widely among the groups.
Studies of the Indians’ origins are another sore point. The peopling of the Americas—how Indians came here and when—has been the subject of countless Ph.D. theses and scientific articles. The thrust of the genetic and archaeological evidence is that the ancestors of Native Americans walked or paddled from Siberia between 13,000 and 17,000 years ago, at the height of the last ice age. But any Native American of a traditional bent already knows where he or she came from. Unless the knowledge has been lost, each tribe has a story of its creation. The Havasupai, for instance, believe their ancestors emerged from beneath the earth of the Grand Canyon.
“Some people have an insecurity because their beliefs are being threatened,” said Francine Romero, an Indian health researcher who specializes in population genetics. “The fear is that the research is going to cast doubt not only on who they are but also on their relationship to their environment. But I still rely on my traditional beliefs. The two are complementary for me. One hundred years from now, what we know about science will have changed too.”
The present scientific understanding is that the starting point of all human beings is in East Africa. Our genes originated and evolved there, and more variants emerged as we dispersed. Native Americans, therefore, are the youngest people in the world, having been the last to break off from the migratory pathway of humanity. But where on the pathway do the Indians’ diseases arise?
One line of argument holds that a condition like type 2 diabetes, because it occurs in populations everywhere, was a latent passenger on the journey from Africa. The diabetes-susceptible genotypes, according to this theory, are old. Another argument is that the Darwinian pressure upon the Asians who struggled through the ice to the New World was so extreme that most didn’t survive. Group DNA was forced into a genetic bottleneck, which stripped the old baggage away. What emerged on the far side was a rare suite of genetic variants that have since expanded in Native Americans. Accordingly, the Indians’ brand of diabetes is theirs alone. It may be different from the condition in Europe or in Africa, though the environmental triggers are the same.
A study by Williams has thrown a beam of light on the ancient liabilities. After typing the markers for ancestry in several thousand Pimas, Williams put the results in order, ranging from full-heritage Indians to the highly admixed. Then he turned to the medical records. Pimas who had the most gene variants from European American sources were least likely to have diabetes. Conversely, the full-heritage Pimas, the most “Indian” in biological terms, were most at risk. European blood for some reason was modestly protective.
| AFRICAN AMERICANS | FINNS | NATIVE AMERICANS | |
| Hallmark trait (also pertains to other groups) | Sickle-cell anemia | Lactose intolerance | Type 2 diabetes (genes unknown) |
| Aboriginal population | Africa | Africa | Africa |
| Historical migration to | the Americas | Finland | the Americas |
| Genetic variation within group | High | Low | Low |
| Single-gene disorders wtih increased frequency | Sickle-cell anemia, thalessemia, and a related blood disorder | Northern epilepsy and nearly 40 others | Cystic fibrosis, albinism, and a few others |
| Common diseases with increased prevalence | Type 2 diabetes, heart disease, obesity, and prostate cancer | Type 2 diabetes, heart disease in East Finland | Kidney disease, heart disease, and highest rate of type 2 diabetes |
| Attitude toward disease genes | Fearful of stigma | Part of national heritage | Suspicious of researchers |
| Gene-testing experience | Apprehension due to testing in 1970s for sickle-cell trait | Screening and counseling available | Fear of exploitation; lawsuit regarding genetic studies filed |
| Group’s own health focus: genes versus environment | Environment | Both | Environment |
What to expect in the future:
Elimination of all ethnic and racial categories in favor of individual genotyping for disease risk
