How can we trace our ancestors?Scientists can use patterns of DNA variation in modern populations to trace the movement of our ancestors around the world. In many parts of the world, people still live in the same area as the ancestors who first went there. But modern populations are mixing more and more, so there is a race against time to collect DNA samples before this evidence is lost.
History or her-story?
The mitochondrial DNA of the inhabitants of Polynesian islands in the Pacific Ocean is more similar to people from South East Asia than to people from South America. This shows that the Polynesians' ancestors probably came from Asia, not South America, as some people once thought. However, studies of Y-chromosome DNA of the inhabitants of Polynesian island Rarotonga reveal that a third of the population have European male ancestors – possibly eighteenth-century sailors.
Want to be decoded?
Icelandic doctor Kári Stefansson set up his own company – deCODE Genetics – in 1996 to create a giant electronic database of genetic information on every citizen in Iceland, a country where the population was isolated for 1000 years. DNA samples were collected from volunteers and analysed to look for gene variants that affect their predisposition to disease. You can also send them a cheek swab and they claim to be able to analyse your DNA to calculate your risk to diseases.