Australasian Science: Australia's authority on science since 1938

Genetic Ancestry

By Michael Cook

The thriving business of DNA ancestry testing is hawking dreams, not science.

Michael Cook is editor of the online bioethics newsletter BioEdge.

The full text of this article can be purchased from Informit.

23andMe.com, a California-based genetic testing company, spruiks ancestry testing on its website. For US$99 you can discover the composition of your ancestors, your genetic relatives, your maternal and paternal lineages, and even the percentage of your DNA that comes from Neanderthals.

“Trace Your Family Lineages Back 10,000 Years and Beyond,” it says. “Find out if you share an ancestor with famous figures such as Marie Antoinette and Thomas Jefferson.”

Similar companies are springing up everywhere – to the enrichment of some geneticists and the dismay of others. Five years ago three US scientists described ancestry tests in the New England Journal of Medicine as “premature attempts at popularising genetic testing”. One of them called the tests “recreational genomics”.

Even more huffy was a British geneticist, Dr Mark Thomas of University College London, who wrote in The Guardian recently that most of these claims were better described as “genetic astrology”. All that tests can establish is a statistical probability of my lineage. Just because I share a certain genetic marker with residents of a certain area does not mean that my ancestors came from there.

Nor is the fact that Napoleon and I may share a marker meaningful. One study published in Nature in 2004 estimated that the most recent common ancestor of everyone alive today lived only...

The full text of this article can be purchased from Informit.