American and Israeli geneticists have developed an algorithm that can help reveal men’s surnames from their Y-chromosome DNA, passed down from father to son.
A team led by Dr Yaniv Erlich, of the Whitehead Institute for Biomedical Research in Massachusetts, tested the algorithm on the DNA samples of 911 men in the United States. The samples were compared with DNA ancestry databases on the internet containing the genetic sequences of 135,000 men with the most common surnames in the US, most of them of European origin. The algorithm identified the surname in up to 18% of cases. This might not sound overly impressive, but when the surname is cross-referred with other personal data freely available on the web it can trace an individual fairly accurately – particularly if the surname is unusual.
As an experiment, the team applied the algorithm to the genome sequence of American geneticist Craig Venter, a pioneer in sequencing the human genome. The algorithm identified the Venter surname and narrowed him down to one of two Venters living in California sharing the same genetic signature. Dr Erlich also scanned the Y-chromosomes of Utah men who had submitted their DNA sequences to the 1000 Genomes Project. Cross-referring them to matches in genealogy databases, he got the surnames of their paternal and maternal grandfathers, and by doing a Google search for their obituaries, he got the individuals’ family trees.
This is not the first work done on identifying surnames from DNA alone. In 2008, UK geneticist Dr Turi King of the University of Leicester found that men with the same British surname are highly likely to be genetically linked. While this sounds intuitively obvious, her research showed that two men who share the same surname have a 24% chance of sharing a common ancestor; this increases to 50% if the surname is rare. Dr King looked for similar Y-chromosome haplotypes among 2,500 men with 500 different surnames, making sure she excluded their known relatives. She found that men with certain rare surnames, such as Attenborough and Swindlehurst, shared the same or near identical Y chromosome types in over 70% of cases.
As DNA ancestry databases continue to grow rapidly online, research tools and techniques employed by geneticists like Erlich and King will eventually refine matches between surnames and Y-chromosome profiles with pinpoint accuracy. While this is a concern to privacy advocates, it will be a gift to forensic experts who can put a name to both modern and historic human remains from their DNA alone.