A new study has revealed the first fine-scale genetic map of Ireland. It shows ten distinct clusters of shared ancestry within the island, roughly aligned with ancient Provinces and major historical events.
The study used a combination of DNA from 196 Irish individuals with four generations of ancestry linked to specific areas across the island. The data are now being compared with thousands of reference population samples from across Europe.
Origins
Ireland is a small island off the North-Western seaboard of Europe. That geographic situation has created a genetic environment that is conducive to genetic homogeneity and isolation, as evidenced by a number of inherited traits at high frequencies within Irish populations compared with Europeans in general.
In the ancient period, people arrived in Ireland from other parts of the continent and began farming. These new farmers brought with them cattle, cereals and ceramics. They also displaced local Mesolithic hunter-gatherers who had a striking combination of dark skin and blue eyes.
These people were referred to as Proto-Gaels and they became the distinctive Gael identity. However, modern residents of Scotland and Ireland don’t share much DNA with these early settlers. Instead, their ancestors can trace most of their genetic makeup to the Celtic tribes that expanded from Central Europe at least 2,500 years ago. They thrived throughout Europe for thousands of years before being disrupted by other groups, including Germanic peoples and the Viking Invasions.
Migrations
Ireland’s history has left its mark on the genome of its people, and a greater understanding of the DNA within Ireland can help researchers identify genetic markers that predict disease. This can be useful for developing more effective treatments, and can even aid in the identification of diseases in populations with high rates of a particular disease.
In the early years of settlement in Ireland, a wave of migration was driven by the end of the Ice Age. This was caused by warmer temperatures and the formation of land forms connecting Ireland to parts of Scotland and North-West England.
Using whole-genome analysis, scientists from Trinity College Dublin and Queens University Belfast found evidence of both stone age settlers with origins in the Fertile Crescent, and bronze age economic migrants from eastern Europe who arrived as part of a major movement of population. These changes occurred around 12,000 years ago, during a period when the ice sheet was retreating.
Diseases
Irish dna can be traced back to people who came to Ireland from Central Europe around the time of the Viking invasion. But it also comes from ancestors of ‘Celtic’ tribes who headed north, colonizing the upper Rhine, spreading into Belgium and the Netherlands and crossing the Alps to Northern Italy.
This genetic lineage is still present in Irish people today, and is associated with higher rates of cystic fibrosis, celiac disease and galactosemia – metabolic diseases that prevent the breakdown of carbohydrates. Fortunately, these are all treatable conditions.
The Irish population has a significant amount of genetic variation, particularly in Y-chromosome and mitochondrial DNA. Y-chromosome haplotype diversity shows a general east-west cline10, with hegemony in the northern region of the country.
This is consistent with previous work which found little Y-chromosome introgression from Britain in the modern Irish population, and suggests that most of the genetic diversity within Ireland has been driven by migration from the mainland. However, the researchers warn that further study of regional populations is necessary to reveal how diversity developed.
Ancestry Tests
If you’re looking to find out where your Irish ancestors came from, an ancestry DNA test is a great place to start. Using genetic data along with family records, you can piece together a detailed genealogy.
Many people who take a Y-DNA or mtDNA test find that they can pinpoint their specific ancestry roots and confirm family stories. You can also use the results to discover new cousins who share your DNA.
The island of Ireland has undergone dramatic changes throughout the centuries. During the 8th century, the Viking invasion heavily influenced the island’s culture, introducing Norwegian ancestry to the population.
A recent study found that the Norse Vikings influenced the earliest Irish people in a way that is still seen today. This can be observed in the DNA of ancient tombs.
Y-DNA and mtDNA tests are particularly useful for pinpointing specific origins within Ireland. These can help identify a surname or a particular region in the country where your paternal line originated.