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
landmark2 results are published today in international journal
Proceedings3 of the National Academy of Sciences, USA.
Ireland has
intriguing4 genetics. It lies at the edge of many European
genetic1 gradients with world maxima for the
variants5 that code for lactose
tolerance6, the western European Y
chromosome7 type, and several important genetic diseases including one of excessive iron
retention8, 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
embarking9 on a type of genetic time travel.
Migration10 has been a hot topic in
archaeology11. Opinion has been divided on whether the great transitions in the British
Isles12, from a hunter-gatherer lifestyle to one based on agriculture and later from stone to metal use, were due to local
adoption13 of new ways or whether these influences were
derived14 from
influxes15 of new people.
These ancient Irish genomes each show unequivocal evidence for massive migration. The early farmer has a majority
ancestry16 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.