Where on Earth are you from?

By Rebecca Priestley In Science

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Reconstruction of Asian hunters’ migration across the Bering Strait. Getty Images

This article was first published on February 19, 2014.

The first of my ancestors to arrive in New Zealand was Anders Haeckel, a young Finn who sailed to New Zealand with the British Merchant Navy. In 1892, he went gum digging in Northland, then tried his hand at gold mining on the West Coast. He settled in Hokitika, where he married and raised a family. His youngest daughter, Gertrude, was my grandmother.

Maori genealogical narratives go back many more generations than this, suggesting, along with radiocarbon dating of the earliest burial sites, that the first Polynesians arrived here some 800 years ago. But how many were there? And where did they come from?

The pattern of mutations in the DNA of modern humans reveals that if you go back far enough, we all came from Africa – all people alive today have a common ancestor who lived in Africa 160,000 years ago. About 60,000 years ago, our human ancestors began to migrate out of Africa. Recent discoveries suggest that as they travelled, they occasionally interbred with other hominids, such as Neanderthals and Denisovans.

Work by population geneticist Spencer Wells, director of the National Geographic’s Genographic Project, and Lisa Matisoo-Smith, professor of biological anthropology at University of Otago and the Genographic Project’s Oceania investigator, is filling in the gaps between family genealogies and the broad narratives about our species’ journey from Africa. Wells recently visited the East Coast with Matisoo-Smith to give results to participants who provided DNA samples to Matisoo-Smith last year and to listen to migration and genealogical narratives from a group of Ngai Tamanuhiri at Muriwai Marae.

Piecing together the Polynesian puzzle: Lisa Matisoo-Smith and Spencer Wells.

The Genographic Project began in 2005, with a focus on analysing mitochondrial DNA, or mtDNA, which is inherited along maternal lines, and Y-chromosomes, which pass down paternal lines.

Genetic mutations accumulate over time and are passed down through generations, so the more mutations two individuals have in common, the more closely they are related, and vice versa. Combining genetic information with geological and archaeological data allows scientists to recreate the migration patterns of our ancestors.

The project’s current maps of human migration show lots of detail in Europe, Africa and the Middle East, but little or nothing in Polynesia.

“A focus in the first phase of the project was working with indigenous groups to collect samples to give us the broadest glimpse of human migration patterns,” says Wells. Most of that work is now complete, with Polynesia – which has many distinct indigenous groups living across hundreds of small islands – one of the last pieces in the puzzle.

“New Zealand is fascinating,” says Wells. “If you think about the broad sweep of human migration, the last major place to be settled was New Zealand. Only about 800 years ago, the Polynesian ancestors migrated, probably from somewhere around present-day French Polynesia, perhaps the Cook Islands, and settled New Zealand.”

Adding more detail to migration history involves gathering more DNA samples. Matisoo-Smith’s own project, From Aotearoa to Africa – funded by the Genographic Project, a James Cook Fellowship and the Allan Wilson Centre – involves sampling 2000 New Zealanders to identify population origins and interactions between Maori and more recent immigrants. Although the Genographic Project focuses on indigenous communities, Matisoo-Smith is looking at people from all over the country “to give us a picture of the diverse ancestry of all New Zealanders, not just the first arrivals”.

Alongside its research focus on indigenous groups, the Genographic Project is open to anyone who buys a self-testing kit. The latest phase, Geno 2.0, uses new technology to examine up to 130,000 ancestry-informative markers across your entire genome.

Out of Africa: migration patterns of early human beings. Image/National Geographic Genographic Project

As well as telling you what percentage of your ancestry comes from which geographic region, it can reveal how much of your DNA is Neanderthal or Denisovan. Unless you’re African, says Wells, it’s likely that “two to two and a half per cent of your genome traces back to these hominids”.

Wells’ goal with the Genographic Project, is “to create a seamless experience from what people know about recent family history, through written history back to the really, really deep stuff that happened prior to 10,000-20,000 years ago. We know a fair amount about the very early migrations, and we’re focusing on the patterns in the middle right now. That’s what I think many people are particularly interested in – when groups start to take on modern cultural identities and present-day languages developed.”

When my mtDNA was tested in 2005, the Genographic Project told me my ancestors “entered Europe around the time of the Neolithic 10,000 years ago”.

When my Geno 2.0 test results arrive, I expect to find I have genetic markers for the Finnish, Swedish, English, Scottish and Irish ancestry I know about from family history. I’m also hoping for a few surprises.

The Genographic Project

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