Tuesday, February 21, 2006

New Study discusses linking surnames to Y chromosome DNA in criminal investigations

From the BBC: http://news.bbc.co.uk/1/low/sci/tech/4736984.stm

"Forensic scientists could use DNA retrieved from a crime scene to predict the surname of the suspect, according to a new British study. It is not perfect, but could be an important investigative tool when combined with other intelligence. The method exploits genetic likenesses between men who share the same surname, and may help prioritise inquiries.

The technique is based on work comparing the Y chromosomes of men with the same surname. The Y chromosome is a package of genetic material found only in males."

Abstract from Current Biology:
Curr Biol. 2006 Feb 21;16(4):384-388.
Genetic Signatures of Coancestry within Surnames.
King TE, Ballereau SJ, Schurer KE, Jobling MA.
Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom.

Surnames are cultural markers of shared ancestry within human populations. The Y chromosome, like many surnames, is paternally inherited, so men sharing surnames might be expected to share similar Y chromosomes as a signature of coancestry. Such a relationship could be used to connect branches of family trees , to validate population genetic studies based on isonymy , and to predict surname from crime-scene samples in forensics . However, the link may be weak or absent due to multiple independent founders for many names, adoptions, name changes and nonpaternities, and mutation of Y haplotypes. Here, rather than focusing on a single name , we take a general approach by seeking evidence for a link in a sample of 150 randomly ascertained pairs of males who each share a British surname. We show that sharing a surname significantly elevates the probability of sharing a Y-chromosomal haplotype and that this probability increases as surname frequency decreases. Within our sample, we estimate that up to 24% of pairs share recent ancestry and that a large surname-based forensic database might contribute to the intelligence-led investigation of up to approximately 70 rapes and murders per year in the UK. This approach would be applicable to any society that uses patrilineal surnames of reasonable time-depth.


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