Study: Ability to link DNA, history grows
NEW YORK — About 60 percent of the U.S. population with European heritage may be identifiable from their DNA by searching consumer websites, even if they’ve never made their own genetic information available, a study estimates.
And that number will grow as more and more people upload their DNA profiles to websites that use genetic analysis to find relatives, said the authors of the study released Thursday by the journal Science.
The use of such databases for criminal investigations made headlines in April, when authorities announced they’d used a genetic genealogy website to connect some crime-scene DNA to a man they then accused of being the so-called Golden State Killer, a serial rapist and murderer.
In general, such searches begin on a site by finding a relative linked to a DNA sample. Then sleuths can use other information like published family trees, public records and lists of survivors in obituaries. They can build speculative family trees. Eventually, that can point to someone whose DNA is then found to match the original sample.
With DNA databases “you need just a minute fraction of the population to really identify many more people,” said Yaniv Erlich of Columbia University, an author of the study.
His paper focused on Americans of European descent because such people are over-represented in DNA databases, which makes it easier to find relatives.
The researchers started with the 1.28 million participants on the Myheritage site.
About 60 percent of the time, they found someone whose genetic similarity was at least equal to that of a third cousin, similar to the degree of relatedness that led to the Golden State Killer suspect.
With some basic assumptions about what kind of data would be available for a criminal suspect, the researchers calculated they could pare the possible identity of the initial person to just 16 or 17 people. That’s limited enough that police could zero in with further investigation, Erlich said.
Erlich and his co-authors suggested that such searches could cast a broader net in the near future.