-------- Original Message -------- Subject: DNA may tell police the surname of the criminal Date: Wed, 22 Feb 2006 13:09:16 +0000 From: Brian Randell <[EMAIL PROTECTED]> To: [EMAIL PROTECTED]
Hi Dave: >From today's (UK) Guardian: >How DNA may tell police the surname of the criminal > >Alok Jha >Wednesday February 22, 2006 >The Guardian > >Police will soon be able to predict the surnames of criminals whose >DNA is found at crime scenes, according to research published >yesterday. The technique would only work in finding men, however, as >it is based on identifying similarities in the Y chromosome, which >is passed from father to son. > >The technique relies on research carried out by University of >Leicester scientists into how Y chromosomes have spread through the >British population. They analysed these chromosomes in 150 pairs of >men with the same surname and found that, in a quarter of cases, the >pair had matching Y chromosomes. > >When the most common names were excluded from the list - Smith, >Jones, Williams and Taylor, for example - the chance that two men >with the same surname shared a Y chromosome jumped to 50%. The >research appears in the latest edition of Current Biology. > >Mark Jobling, a geneticist at the University of Leicester who led >the work, said the police would need a relatively small collection >of male DNA - around 40,000 people - to allow useful matches to be >made. "That sounds big but the national DNA database is nearly 100 >times bigger," he said. By matching the Y chromosome details of >unidentified DNA at a crime scene with the database, police would >get a list of potential surname matches. > >"That would allow you to prioritise suspects in your investigation," >said Dr Jobling. "If you have a lot of suspects - say a whole town >or something - you can say we have 50 names, are these names >represented here, if so let's go and interview these people." > >Y chromosomes are passed from father to son mostly unaltered. Once >in a while, they will acquire random mutations as they pass through >the generations. Some parts of the chromosome are known to mutate >less rapidly than others and, by mapping these differences, >scientists can create a tree showing the relationships between >different Y chromosomes. > >"If men fall in different branches of the tree, there's no way they >can be related to a recent male ancestor," said Dr Jobling. "If they >lie within the same branch, there is a chance they are, but it >doesn't prove it. > >"When we do that simple test, we find that a highly statistically >significant excess of pairs share a branch of the tree, much more >than we expect by chance." > >It is a surprising result, since there are plenty of reasons why >people might have the same surname but be unrelated: many names were >founded by more than one man, for example. There is also the issue >of illegitimacy. The researchers predicted that more than 1% of >children were illegitimate in each generation. Over many >generations, this could have built up a significant error. > >"Those two elements would act as a strong force to break any links," >said Dr Jobling. "It was a surprise that by choosing just pairs we >got a clear signal of sharing ancestors." http://www.guardian.co.uk/crime/article/0,,1715022,00.html -- School of Computing Science, University of Newcastle, Newcastle upon Tyne, NE1 7RU, UK EMAIL = [EMAIL PROTECTED] PHONE = +44 191 222 7923 FAX = +44 191 222 8232 URL = http://www.cs.ncl.ac.uk/~brian.randell/ ------------------------------------- You are subscribed as [email protected] To manage your subscription, go to http://v2.listbox.com/member/?listname=ip Archives at: http://www.interesting-people.org/archives/interesting-people/
