Indigenous people around the world will be asked to supply a cheek swab to help geneticists answer the question of how humanity spread from Africa, the National Geographic Society and IBM said on Wednesday. They hope to sample 100,000 people or more and look for ancient clues buried in living DNA to calculate who came from where and when. The five-year Genographic Project will use sophisticated laboratory and computer analysis. IBM will provide supercomputing and technical equipment and the philanthropic Waitt Family Foundation, established by the founder of Gateway computers, will fund field research. For $100, anyone who wants to can supply his or her own cheek swab for a personalized analysis and perhaps to contribute to the research. Researchers will be sampling 10,000 people from 10 sites across the world. For instance, scientists are not sure how the Americas were first populated, said Ajay Royyuru, the lead scientist for IBM. The first people may have come from Siberia and eastern Asia, or they may have been Europeans migrating over a frozen north Atlantic, he said. "The goal of the project is to learn the journey that our ancestors traveled and hopefully answer the question of who we are and how we happened to be where we are," he said. "We all came out of Africa, but how did we get to where we are today?" asked geneticist and anthropologist Spencer Wells. "What we are aiming for is the story of everybody." Experts in related fields such as population genetics, archeology, evolution science, linguistics and paleontology will help in the five-year project. Fossils provide some clues about where people settled as they evolved and moved from Africa to colonize every continent except Antarctica. But mysteries remain, for example, about how people first got to Australia 50,000 to 60,000 years ago, or when and from where the first humans arrived in the Americas. Linguistics and DNA provide many clues, but the so-called Genographic Project will aim to systematically look at all peoples on all continents. Teams in China, Russia, India, Lebanon, Brazil, South Africa, Paris, Britain and Australia have signed on to help. Some groups may be hostile to the effort, Wells said in a telephone interview. "There has been a history of exploitation of indigenous groups around the world," he said. But, he added, experts on dealing with various groups will help sell the idea. "It's a question of explaining the science," he said. Geneticists will look at little changes in DNA code that have been used by experts to trace human history. Mitochondrial DNA, handed down virtually unchanged from mothers to their children, is one source that was used to calculate the so-called ancestral Eve, who would have lived in Africa about 180,000 years ago. Men have their own version, found in the Y chromosome, which is inherited with very little change from father to son. Tiny mistakes in the code that occur with each generation can be used as a kind of genetic clock to track backward. People who buy the mail-in swab kit are unlikely to add to the indigenous people's database, but can find out something about their own ancient ancestry and perhaps add to the effort, Wells said.