Saturday, 5 May 2012


Courtesy of Clara Hoyne, Clare Roots Society Secretary,
who 'flagged' this article...

Discover your genetic ancestors


WHOSE BLOOD courses through your veins? Could you be a descendant of a Viking warrior or a Berber pirate? Or perhaps you are related to the Uí Neill chieftains or the kings of Laighin (Leinster)?

If so your genes will carry the proof, and a new company set up by scientists offers a service that can reveal your genetic heritage.

Today sees the launch of "Ireland's DNA", a direct to customer genetic ancestry service. "We are planning it as a national project. The more people that get involved, the more we can understand about Irish history from the resulting dataset," says Dr Gianpiero Cavalleri, one of three founders of the company.

Cavalleri is a biomedical research lecturer at the Royal College of Surgeons in Ireland and heads its epilepsy genetics group. The Irish project grew out of a similar undertaking that started about six months ago in Scotland.

And that in turn came out of a book examining the genetic ancestry of Scotland, The Scots: A Genetic Journey. The authors were Dr James Wilson, a geneticist at the University of Edinburgh who works on the genetic roots of disease, and historian Alistair Moffat.

"There was huge public interest in the book," Dr Cavalleri says, so much so that the three decided to set up a company, Scotland's DNA, to help finance further study of the country's collective genome.

"Now we are going to use the same concept for Ireland," he says. He got the idea some years ago while at Stanford University. He became fascinated with the idea that you could identify past human migration by looking at the male-only part of the genome, the Y chromosome.

As males of a given lineage began their migration out of Africa, some would have been more successful than others. Untold numbers would have been killed off, but many continued to branch out into Europe and Asia. Successful migrants would have left their mark behind in the Y chromosome.

He realised that people were interested to know their links to past generations. "With DNA you can really go deep into the past to learn where your ancestors came from," he says.

A decade ago it was tremendously expensive to deliver a complete genome but today prices have fallen and it is feasible to think of using DNA technology to identify ancestry. About 20,000 genomes have been completed so far by labs around the world and this has opened up the possibility of direct Y chromosome comparisons between individuals and groups.

The more genomes completed, the more the resolution improves, and the better the ability to see back in time. "Up until recently we might have had a genetic signature for the northwest of Ireland collectively as being Irish. What has happened since is we can split up the Irish type. The higher resolution comes from the sequencing of the human genome."

It all comes down to comparisons. "We look for markers and see what they are telling us," he says. "A marker is part of the DNA that is different between people. Those differences arise with each generation."

Most of our genome is a mix of our mother's and father's DNA, but the Y chromosome does not mix in a substantial way. Cavalleri likens it to the Olympic torch as individual runners carry it from city to city on the way to the games.

The same torch is passed from person to person but imagine that each person is able to leave behind a mark on the torch, a small spelling change in the DNA. "By looking at those spelling changes you get a sense of how those people have moved. After all, we are part of one big pedigree." It is all about knowing what markers are hidden in a genome pointing towards one ancestry or another.

You can read the full article here...

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