"Scientists at Leicester University, where DNA fingerprinting was invented in 1984, said they had demonstrated that men with the same surname were highly likely to be genetically linked. The finding could help genealogy researchers as well detectives investigating crimes using traces of DNA found in blood, hair, saliva or semen.
The technique is based on analyzing DNA from the Y chromosome that imparts maleness and which, like last names, is passed down from father to son. "
The likelihood of a good genetic match depends on the rarity of the name, with the most unusual names having the strongest links. A study of 2,500 men found that on average there was a 24 percent chance of two men with the same last name sharing a common ancestor but this increased to nearly 50 percent when the last name was rare. Over 70 percent of men with last names such as Attenborough and Swindlehurst shared the same or near identical Y chromosome types.