First ancient Irish human genomes sequenced

December 28, 2015
Excavated near Belfast in 1855, she had lain in a Neolithic tomb chamber for 5,000 years; subsequently curated in Queens University Belfast. Credit: Daniel Bradley, Trinity College Dublin

A team of geneticists from Trinity College Dublin and archaeologists from Queen's University Belfast has sequenced the first genomes from ancient Irish humans, and the information buried within is already answering pivotal questions about the origins of Ireland's people and their culture.

The team sequenced the genome of an early farmer woman, who lived near Belfast some 5,200 years ago, and those of three men from a later period, around 4,000 years ago in the Bronze Age, after the introduction of metalworking. Their landmark results are published today in international journal Proceedings of the National Academy of Sciences.

Ireland has intriguing genetics. It lies at the edge of many European genetic gradients with world maxima for the variants that code for lactose tolerance, the western European Y chromosome type, and several important genetic diseases including one of excessive iron retention, called haemochromatosis.

However, the origins of this heritage are unknown. The only way to discover our genetic past is to sequence genomes directly from ancient people, by embarking on a type of genetic time travel.

Migration has been a hot topic in archaeology. Opinion has been divided on whether the great transitions in the British Isles, from a hunter-gatherer lifestyle to one based on agriculture and later from stone to metal use, were due to local adoption of new ways or whether these influences were derived from influxes of new people.

A reconstruction of the Ballynahatty Neolithic skull by Elizabeth Black. Her genes tell us she had black hair and brown eyes. Credit: Barrie Hartwell.

These ancient Irish genomes each show unequivocal evidence for massive migration. The early farmer has a majority ancestry originating ultimately in the Middle East, where agriculture was invented. The Bronze Age genomes are different again with about a third of their ancestry coming from ancient sources in the Pontic Steppe.

"There was a great wave of genome change that swept into Europe from above the Black Sea into Bronze Age Europe and we now know it washed all the way to the shores of its most westerly island," said Professor of Population Genetics in Trinity College Dublin, Dan Bradley, who led the study, "and this degree of genetic change invites the possibility of other associated changes, perhaps even the introduction of language ancestral to western Celtic tongues."

"It is clear that this project has demonstrated what a powerful tool ancient DNA analysis can provide in answering questions which have long perplexed academics regarding the origins of the Irish," said Dr Eileen Murphy, Senior Lecturer in Osteoarchaeology at Queen's University Belfast.

The video will load shortly

Whereas the early farmer had black hair, brown eyes and more resembled southern Europeans, the genetic variants circulating in the three Bronze Age men from Rathlin Island had the most common Irish Y chromosome type, blue eye alleles and the most important variant for the genetic disease, haemochromatosis.

The latter C282Y mutation is so frequent in people of Irish descent that it is sometimes referred to as a Celtic disease. This discovery therefore marks the first identification of an important disease variant in prehistory.

"Genetic affinity is strongest between the Bronze Age genomes and modern Irish, Scottish and Welsh, suggesting establishment of central attributes of the insular Celtic genome some 4,000 years ago," added PhD Researcher in Genetics at Trinity, Lara Cassidy.

Explore further: 'Fourth strand' of European ancestry originated with hunter-gatherers isolated by Ice Age

More information: Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome,

Related Stories

Ancient wild ox genome reveals complex cow ancestry

October 26, 2015

The ancestry of domesticated cattle proves more complex than previously thought, reports a paper published today in the open access journal Genome Biology. The first nuclear genome sequence from an ancient wild ox reveals ...

Ancient genome from Africa sequenced for the first time

October 8, 2015

The first ancient human genome from Africa to be sequenced has revealed that a wave of migration back into Africa from Western Eurasia around 3,000 years ago was up to twice as significant as previously thought, and affected ...

DNA reveals the origins of modern Europeans

March 23, 2015

Europe is famously tesselated, with different cultural and language groups clustering in different regions. But how did they all get there? And how are they related?

Recommended for you

Science: Public interest high, literacy stable

October 28, 2016

While public interest in science continues to grow, the level of U.S. scientific literacy remains largely unchanged, according to a survey by the University of Michigan Institute for Social Research.

Experts uncover hidden layers of Jesus' tomb site

October 27, 2016

In the innermost chamber of the site said to be the tomb of Jesus, a restoration team has peeled away a marble layer for the first time in centuries in an effort to reach what it believes is the original rock surface where ...

Important ancient papyrus seized from looters in Israel

October 27, 2016

(—Eitan Klein, a representative of the Israel Antiquities Authority, has announced that an important papyrus document dated to 2,700 years ago has been seized from a group of Palestinian looters who reportedly ...


Adjust slider to filter visible comments by rank

Display comments: newest first

3.7 / 5 (3) Dec 29, 2015
This is very interesting but very tentative, since the data sets are so small. The Neolithic farmer group is represented by a single woman. Since she was buried in a in a substantial tomb, she was probably of high social status and may not be representative of the population.

The Bronze-age group is represented by three men buried on a remote island between Ireland and Scotland, and they may not be representative of the population of Ireland at the time.

Nevertheless, the facts so far are intriguing and dove-tail with important archaeological evidence. We've barely scratched the surface of what can be learned from DNA evidence, and I hope this starts a torrent a follow-up research.
1 / 5 (3) Dec 30, 2015
People do not 'migrate' just to 'get some air'. They migrate out of desperation caused most likely by catastrophic events. The ethnoarchaeologists should look for that cause. Since migration from north of the Black Sea, and from the middle east is suspected, then other cases should be looked for lest these are actually isolated events not constituting a real migration. After all, North America has had some muslim minority for a very long time but never a migration
3 / 5 (2) Dec 30, 2015
North America had tens of thousands of Muslims, brought here as slaves.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.