Scientists' new theory of relativity

Published on 22/02/2006 00:06

TONY Blair and Lionel Blair meeting at a family reunion? Gordon Brown bumping into James Brown at a distant cousin's wedding? The chances could be higher than many people might think.

Researchers now claim men who share the same surname have a one-in-four chance of being related.

So Scottish health minister Andy Kerr could be a kinsman of Simple Minds frontman Jim Kerr. Other unlikely potential pairings include flamboyant Eighties pop star Pete Burns, who had a recent revival on Celebrity Big Brother, and the Edinburgh Labour transport councillor Andrew Burns.

Researchers compared the DNA of 150 pairs of men who share British surnames and found about a quarter were linked genetically. The key, they said, was in the Y chromosome, the part of genetic make-up that defines maleness and is passed from father to son.

However, one large family tree of men sharing the surname is not possible, they said. Several founders for a single name, adoptions, name changes and "non-paternity" (when a man is unaware he is not the father of a child) all confuse matters.

Professor Mark Jobling, of the University of Leicester, who helped conduct the research, said: "One of the practical implications is forensic analysis. It could help police if they have a crime scene with no suspects.

"Police could have a database which would narrow down the pool of suspects and allow them to prioritise. It could be a useful investigative tool."

Brian Sykes, Professor of Genetics at Oxford University and Chairman of Oxford Ancestors, said the development of a Y chromosome database could be crucial in solving crimes where the police have no suspects, such as those of the Yorkshire Ripper. He said: "In cases such as these the DNA could be analysed within two days and either one name or a selection of names could be generated. I think the Home Office should look at this seriously."

But Edinburgh genealogist Neil Wilson thought it was unlikely that men with the same surname were probably related.

He said: "95 per cent of inquiries only go back to the 18th or maybe 17th century history or family tree before records melt into a mass of agricultural labourers.

"You can only trace further back if you are from a noble family or have a very unusual name, but that is very rare. I would be surprised if that many people were related."

John Gow, technical director of Crucial Genetics in Glasgow, said he thought chances of being related were "more like one-in-15 or 20 than one-in-four".

He said: "We are all such a mix of DNA populations these days that not even well-known Scots surnames are more likely to be linked."

The rarer the surname, the greater the chance of random pairs of surnames being related. For example, there is no link for Smith, Jones and Taylor, but a clear link for Attenborough, Widdowson and Grewcock.