Tracing your family with a drop of saliva

Published on Friday 18 September 2009 09:10

Family history usually means delving back a few decades, perhaps a couple of centuries. But there is a new branch of genealogy which can trace your roots far further back. In the final part of our family history series, SUE GYFORD looks at ethno-ancestry – and finds out where two Edinburgh personalities' ancestors were living 30,000 years ago

IT HAS been a long, slow journey to get to Edinburgh – for all of us. Ever since our first human ancestors emerged in Africa more than 100,000 years ago, we have been on the move.

In search of fresh hunting territory, water or vegetation, we inched across the Horn of Africa to the Indian Ocean coast, travelling an average of 1.3 kilometres per generation, and eventually dispersed around the globe.

Now it is possible to tell from just one drop of saliva what path your ancestors took as they migrated from Africa – and population geneticist Dr Jim Wilson is keen to tell you.

Jim, who carries out academic research at the University of Edinburgh, has branched out into what he calls "recreational genetics" – the use of DNA testing by the genealogically curious.

His company, Ethnoancestry, gives people the chance to find out more about their distant ancestors by testing their DNA.

So, if family lore insists that you are descended from the hordes of Genghis Khan or the Pharoahs of Ancient Egypt, this could be your chance to test the theory.

Two people who did were millionaire entrepreneur Sir Tom Farmer, and Cold Case actress Louise Linton, who put their saliva to the test.

SIR TOM FARMER

Sir Tom, 69, has already delved into his genealogy, and so had some idea what his DNA might reveal: "We do have a very good family tree which shows that on both sides we came from Ireland, so I think I would find that I had some Irish descent in me, but I wouldn't know much more."

The results show is that, on his father's side, Sir Tom descended from the Pretani, some of the earliest inhabitants of Britain and Ireland.

Also known as the S145 subgroup, it is the most common group in Britain and Ireland, found in about 45 per cent of Scots and about 60 per cent of the Irish population – which could provide the link to Tom's Irish ancestors.

The group's distinctive marker originally emerged in Iberia, where many people "refuged" in the warmer climate during the last ice age, which peaked around 18,000 years ago, engulfing Britain with freezing temperatures. After the thaw, the Pretani edged north, arriving in Britain between 5,000 and 10,000 years ago – possibly when it was still connected to the rest of Europe by a land bridge.

Jim says: "This is a marker of not being a Viking and not being a Dane, it's descended from the earliest people here, who have been here all that time in these small islands on the edge of Europe."

Tom is, however, a little sad: "I'm a bit disappointed that I'm not something more unusual, but it's nice to know that we have a good, solid stock. I was perhaps hoping for something more individual – I've always been quite aware of my Irish heritage.

"Our grandparents came over from Ireland in the 1850s and stopped in Leith – we've gone back and checked the census, and it's fascinating."

However, the Iberian connection did ring a bell with Farmer family lore, he adds: "We had a great aunt, she had jet black hair and slightly tanned complexion and I swear blind, to my sister and me, my mother used to say, 'Aunt Maggie must have been of Spanish descent.'"

LOUISE LINTON

Filming the latest series of detective series Cold Case in Los Angeles, Louise Linton has awaited her results with anticipation.

The 28-year-old former Fettes College pupil, who was born in Murrayfield, says: "I'm dying to find out my genealogical heritage. It's probably predictable North European, but who knows?"

In fact the DNA test uncovered something a touch more exotic.

Jim discovers that Louise's mitochondrial DNA – her inheritance from her mother's mother and so on, is a subgroup of "group T".

He explains: "This type is most common in Egypt, and other parts of North Africa and the Near East."

Only about 10 per cent of the population of Europe fall into group T, and it is the group that gave humanity one of its greatest gifts – agriculture.

Following the great migration from Africa to the Indian Ocean coastline around 80,000 years ago, Louise's ancestors remained in West Asia, where the group T emerged 30,000 years ago.

They settled in the so-called "fertile crescent", developing farming techniques which they brought with them as they migrated to Europe, beginning 12,000 years ago.

Jim says: "Some of Louise's far-flung relatives were the first people to keep livestock and grow crops. It's the most important event in human history, and it's still very much how we live now – we still eat meat and bread, even though we might not all be growing it now."

There were several waves of migration into Europe and Louise could be descended from any of them, including the Neolithic wave, which started 10,000 years ago and had reached Britain by 5,000 years ago.

They were also among the groups to refuge in the Iberian peninsula during the last Ice Age.

And the prevalence of group T in present-day Egypt means she has some notable distant cousins, according to Jim: "There's no doubt that the ancient Egyptians would have carried this type, because it's so common there," he says.

Louise says the sheer timescales involved had astounded her: "I can't imagine the world 80,000 years ago when my ancestors migrated out of Africa to Southern Arabia and beyond.

"I had no idea that all human lineages originated in Africa. I assumed my ancestors were from somewhere very cold, given how pale my skin is. These test results place my ancestors in continents that truly surprised me, including Africa, and Asia. It's a stunning realisation, and it pleasantly undermines racial differences, knowing we all came from one place."

She adds: "I'm very proud to discover my ancestors invented agriculture and even more so to learn I'm related to the Ancient Egyptians."

For the keen family history hunter, there is still a significant gap between the knowledge we can glean from our DNA and what we find while hunting for the birth certificates of our immediate relatives.

But the field is developing so quickly that Jim thinks the gap will soon be bridged, paving the way for a vast family tree connecting the whole of humanity.

"Genetic ancestry testing has been around since the year 2000, but it was very rudimentary to begin with," he says.

"Even what we can tell you today is quite limited compared with what we could tell you in two years' time.

"At the moment you can potentially go back to only 1,000 years ago – if you have a Viking marker, they arrived in Britain 1,200 years ago so you can take it back to then.

"Eventually it will be possible to take it up to your own family. Every four generations there's a new marker, so the limit is just in how much of the DNA you can read. What we can see today is just the tip of the iceberg."

For more information, go to www.ethnoancestry.com

TV 'gimmicks' that help us understand genetics

"I'm Orcadian so I'd always been interested in the Viking period – and I'm a geneticist. I went to my PhD supervisor and said 'I want to see if we can find Viking DNA, and if there's going to be any it will be in Orkney'."

He succeeded in uncovering the Viking gene, by comparing samples from Norway, Orkney, and several other communities, and his studies were later boosted by the BBC, which funded further work, feeding into the 2001 series Blood of the Vikings.

His TV career has since see him join fashionistas Trinny and Susannah on their three-parter The Great British Body.

He tested volunteers for one of the so-called "fat genes", finding that those with more copies of the gene had a higher average weight than those without – although famously skinny Trinny had one copy, while Susannah had none - proving that it's sometimes possible to overcome your genes.

He says: "It's slightly gimmicky, but I did it because I wanted to take some of this to the public because a lot of them weren't aware that your genes can affect your weight. It's important for scientists to explain their work."

His next TV project is titled Is it Better to be Mixed Race? but the core of his work is vital medical research at the University of Edinburgh.

He is also studying multiple sclerosis, which is found more frequently in Orkney than anywhere else in the world, aiming to tease out the complex contribution of genetics and environmental factors, such as lack of Vitamin D.

HOW THE DNA TEST WORKS

THE chemicals that comprise our DNA are described by geneticists using a string of letters – 3,000 billion letters for each of us, replicated from those of our parents.

When that replication includes errors, we can use them to trace our history, as Dr Jim Wilson of Ethnoancestry, explains: "If you or me were copying out 3,000 billion letters we'd make mistakes, and the machine of the body will also sometimes make a mistake.

"That's a mutation – we call it a variant. So sometimes when you're reading the DNA code you find maybe a letter that's different between you and me and it's those differences that enable us to learn about our ancestors."

Each variation, or marker, is passed on to the next generation, creating a distinct genetic sub-group.

Jim isolates DNA from a saliva sample and identifies his clients' sub-groups.

He then looks at their distribution across the globe and the distribution of further variations and interprets that using archeological and linguistic knowledge of human migrations.

"There's one part that's very quantitative and scientific, and that's deciding what variation someone has, but then of course deciding what they mean is open to some interpretation," he explains.