Posted on 02/22/2006 2:36:46 PM PST by LibWhacker
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.
Details of the research from the University of Leicester, UK, appear in the latest edition of Current Biology.
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 normally only in males.
It is passed down from father to son, just like a surname.
'Cut down'
"The evidence would not be hanging on the Y chromosome, all it would give you is an investigative tool to prioritise a sub-set of your suspects," said co-author Dr Mark Jobling from the University of Leicester.
Mining the information would require building a database of at least 40,000 surnames and the Y chromosome profiles associated with them.
[It] would help you prioritise your suspect list Dr Mark Jobling, University of Leicester Dr Jobling emphasises the limitations of the method; it could have some predictive power in just under half the population, after the most common surnames like Smith, Taylor and Williams have been excluded.
But he says it has the potential to cut down on the police workload.
"If you had a big enough database, it would give you from your crime scene sample a list of names," Dr Jobling, from the University of Leicester, told the BBC News website.
"That would help you prioritise your suspect list. Some investigations have very large suspect lists, in the thousands."
The Leicester researcher said police could consult the Y chromosome and surname database to help prioritise their search in cases where a crime scene sample had failed to turn up matches in the national DNA database.
"You might have a situation where the Y chromosome predicts 25 names. So you could go and see in the pool of suspects whether the names are there," Dr Jobling explained.
"If they are... you could then ask them for a DNA sample and do conventional DNA profiling to see if they match the crime scene sample."
Tested pool
Over time, the Y chromosome accumulates small changes in its DNA sequence, allowing scientists to study the relationships between different male lineages.
It follows that men with the same surname might have very similar Y chromosomes. But adoptions, infidelity, name changes and multiple founders for just one surname complicate the picture.
For the study, Turi King and colleagues from the University of Leicester recruited at random 150 pairs of men who shared a British surname and compared their Y chromosomes.
Across the sample, the authors determined that just under a quarter of the pairs had recent common ancestry.
Given the small sample size and the random recruitment, Dr Jobling said he was surprised at the strength of the signal.
Sharing a surname also significantly raised the likelihood of sharing the same type of Y chromosome, with the link getting stronger as the surname gets rarer.
Added extra
The researchers used the data to roughly test the predictive power of the method. They found the approach was most useful for less common names, with a 34% chance of prediction in the 80 least common surnames from the 150-name sample.
"This range of surnames makes up 42% of the population. So we're looking at prediction in just under half of the population. We have to exclude the Smiths and Joneses," Dr Jobling said.
It can put you more towards or more away from a particular proposition Max Houck, West Virginia University The researchers extrapolated their success rate to the 25-65 no-suspect murders and 300-400 no-suspect rapes on the police books each year, and found the method could help in roughly 10 murders and 60 rapes annually.
Max Houck, a former scientist with the FBI Laboratory, and director of the Forensic Science Initiative at West Virginia University, US, commented: "I think by itself it is probably not useful - a single point of evidence - and for most evidence types that's the case.
"But if you have that and other data, it can put you more towards or more away from a particular proposition if you know the person may have an uncommon surname, and, for example, some ethnicity information.
"If it's a bit more cumulative it might push you in a particular direction," he told the BBC News website.
It was at the University of Leicester in 1984 that the technique of "DNA fingerprinting" was first developed.
Considering the number of changes to a person's surname, especially with women, I wouldn't expect the result to be very accurate. I know a number of people with my surname and there is just about no way on God's green Earth that there is a relation between me and them.
Not to mention adoption and infidelity.
We sure this is not one more pork barrel project slipped into the budget this year?
This would be OK, if not for the illegitimate sons who may not bear the surname....
And they would be involved in this sort of thing, as they would already be b*stards and SOB's to begin with.
How many Mr. Codetoads can there be? j/k
This will soon be shot down by the British equivalent of the ACLU. What it amounts to is a kind of racial profiling.
On the first day of school in the 8th grade, one of the teachers asked one of my friends his name. He said, "John."
She said, "What is your surname?". He said, "Sir John".
How to you track genetically when the perps have no idea what their surname is?
Could they also give me my lucky lotto numbers?
I assume you mean legislators.
I wonder what BJ Clinton's real name is?
My surnames male members have been using DNA for geneology tracing for years.
I actually have a rather evolved answer to this. I'm going to defer it to another time.
I was sued this morning...and am happy that the mediator turned to the plaintiff, and said...Are you out of your freaking mind!!! Cased dismissed!
I love the smell of court in the morning!!! At the the best it smells like......Documentation!
I always thought naming them was kinda' silly. ;)
"I always thought naming them was kinda' silly."
Well, I guess instead of DNA tracing, it would be easier to just put a bell on it.
Who knows? Bill Clinton's name at birth was Blythe, after his putative father (whose marriage to Bill's mother was a bigamous one, since he hadn't bothered to divorce his previous wife), but some people have claimed that Mr. Blythe was still overseas when Bill was conceived.
LOL! Well, since the H1B quota has been increased, it seems whole bunch more lately!
Yeah, not to speak that it's particularly hard to find a female's Y chromosome. ;-)
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