African American DNA Research Forum
A Genealogy of Humankind
Geographic Society Is Seeking a Genealogy of Humankind
Published: April 13, 2005
five-year project to reconstruct a genealogy of the world's populations and the migration paths of early humans from their ancestral homeland in Africa will be started today by the National Geographic Society and I.B.M., the society said in a statement.
The goal of the program is to collect 100,000 blood samples from indigenous populations around the world and analyze them genetically. Researchers at 10 local centers and at the National Geographic Society in Washington will then assign the people who give blood to lineages that trace the routes traveled by their early ancestors.
The program is an effort to accomplish the goals of the Human Genome Diversity Project, an initiative that was proposed by population geneticists in 1991.
That project ran into a political furor that prevented it from receiving substantial government support. It was denounced by some cultural anthropologists, who said that looking for genetic differences among populations was tantamount to racism. And advocates for indigenous peoples portrayed it as a "vampire project" for extracting valuable medical information from the blood of endangered tribes while giving nothing in return.
The proponents viewed their plan as complementing the Human Genome Project, then getting under way, because it would show how the sequence of DNA units in the human genome varied from one population to another. The project did proceed on a more modest basis, eventually collecting blood samples from 52 populations that were converted into 1,000 cell lines. The first major analysis, published in 2002, showed that the subjects' genomes fell into five major clusters corresponding to their continent of origin and, in effect, to their race.
This and many other studies have established that the branches of the human family tree on different continents coalesce to a single root, the ancestral human population that began to migrate from northeast Africa some 50,000 years ago. The routes of this migration are known in general outline but many details remain to be filled in.
The National Geographic's program, if it succeeds, will create a collection of blood samples 100 times larger than the Human Genome Diversity Project did. Dr. Spencer Wells, a population geneticist at the society who is leading the program, said he hoped to head off charges of exploitation by offering money to the tribes for education and cultural preservation.
Many indigenous peoples believe their ancestors have always lived in their home territory, a credo that will not be supported by genetic analysis of their blood samples. Dr. Wells said that he would "tell people up front" that some of the results may contradict what they believe. "The idea that we have all come on a journey from a common origin is intriguing to people," he said.
The program will cost at least $40 million over five years, a National Geographic Society spokeswoman said. Sources of support include the Waitt Family Foundation of San Diego and the income expected from members of the public, who will be encouraged to send in cheek swabs and learn for $99.95 which male or female lineage they belong to.
Male lineages, based on the Y chromosome, and female lineages, based on mitochondrial DNA, are mostly confined to specific continents, reflecting the fact that until recently people mostly lived and procreated in the place they were born.
Dr. Luca Cavalli-Sforza, the Stanford University population geneticist who was a leading proponent of the Human Genome Diversity Project, said the National Geographic effort would "be a major addition to our knowledge." Dr. Cavalli-Sforza, a pioneer of population genetics, is an adviser to the program.
But Dr. Kenneth Kidd, a population geneticist at Yale University, expressed reservations about the plan to preserve the blood samples as raw DNA. Because the DNA is finite, it cannot be shared with every scientist who may ask for some. In the Human Genome Diversity Project, by contrast, white blood cells from a sample were made essentially immortal before storage. Though it would cost an additional $200 to $300 to immortalize each sample, the cells last forever and the supply is inexhaustible.
The National Geographic program will develop a lot of useful information "but to me it is not a properly and fully developed kind of study" because the samples cannot be made available to everyone in the scientific community, Dr. Kidd said.
Dr. Wells said a large amount of DNA would be available from the 5 to 10 milliliters of blood drawn in each sample. He cited the extra cost of making permanent cell lines and also said that some indigenous peoples opposed the notion of having their cells live on after their deaths.
Besides tracing the routes of early human migrations, the National Geographic program will study other questions of population history like the origin of the Han Chinese, the lost homeland of the Indo-European languages and whether a genetic trail was left by the armies of Alexander the Great.
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