A new study, led by RCSI and the University of Edinburgh, which examined the genetic structure of the Irish Traveller community, has confirmed that Travellers are very much of Irish ancestral origin and, for the first time, gives an objective estimate of when Travellers split from the ‘settled' population in Ireland.

This research, which will help to inform the history of the Traveller community, comes as the Irish State is expected to formally recognise Travellers as an ethnic group.

This population-based genetic study, also featuring researchers from University College Dublin and the Hebrew University of Jerusalem, explored the history and structure of the Traveller population in the context of ‘settled' Irish, neighbouring European and Roma Gypsy groups. The study has been published in the journal Scientific Reports.

Irish Travellers account for approximately 0.6% of the Irish population, consisting of between 29,000-40,000 individuals. They are a population with a history of nomadism, where cousin marriages (consanguineous marriages) are commonplace and they are socially isolated from ‘settled' Irish people. 

This landmark research, using DNA from a sample Irish Travellers, European Roma and settled people, has:

• Found that at a genetic level, Travellers are very close to settled Irish people, but show significant differences;
• Found no evidence for a recent shared ancestry between Irish Travellers and European Roma;
• Estimated the time when Travellers diverged from the settled population: approximately 12 generations (360 years) ago
• Shown subtle genetic differences between speakers of the Cant and Gammon dialects of the Traveller language.
• Found that the proportion of Traveller genomes where the maternal and paternal copies are identical was on a par with similar consanguineous populations in other countries.

The research shows small but significant differences in the genomes of Irish Travellers and those of the settled population. It provides evidence, suggested by previous studies, that the genes of Irish Travellers are closer to the settled Irish population at a genetic level, as opposed to the common misconception that Travellers are a hybrid population of settled Irish and European Roma. The genetic distance that exists between Travellers and the settled population can be attributed to genetic drift, brought on by hundreds of years of genetic isolation combined with a decreasing population size.

The research also estimates for the first time when the Traveller population split from the settled Irish. Another misconception is that Travellers were displaced due to the Great Famine (1845-1852) however, by using several different genetic dating methods, the researchers' estimate that the separation began around 12 generations ago. This translates into approximately 360 years, dating back to the mid 1600s.

Speaking on the research, Professor Gianpiero Cavalleri, Associate Professor in Human Genetics at RCSI's Department of Molecular and Cellular Therapeutics said, "Our findings give an important insight into the demographic history of Irish Travellers. The findings confirm that the Irish Traveller population has an Irish ancestry and this comes at a time where the ethnicity of Travellers is being considered by the Irish State. It is important to emphasise that although Irish Travellers show clear features of a genetic isolate, they are genetically very close to settled people in Ireland. It is also interesting to observe that the isolation of Travellers from settled people predates the Great Famine. However it's important to emphasise that our research estimates the beginning of the social divergence of the Travelling community, rather than their origin."

Consanguineous marriages are common amongst the Travelling community. This, combined with genetic drift due to genetic isolation, has led to an increased prevalence of particular genetic diseases including galactosaemia. What was not known, until now, was the degree to which this cousin marriage had influenced the genome.

The study has found that in terms of the inheritance of identical stretches from both parents, the Irish Traveller genomes are very similar to other consanguineous populations around the world, such as the Balochi of Pakistan, the Druze of the Levant and European Roma. All the data point to the Irish Travellers being a genetic isolate who could potentially be valuable for understanding the genetic risk factors for disease in Ireland - both among travellers and settled people.

The research was also welcomed by author and Traveller activist, Michael McDonagh said, "As a Traveller who has spoken on the history and identity of Irish Travellers to many groups ranging from children to academics, you sometimes rely on anecdotal information in trying to put across a serious message about Irish Traveller history. I am delighted that now we have qualified evidence that substantiates the argument I have made for many years, which is that Travellers did not descend from the Famine in Ireland. This research allows us to bring Irish Traveller history back many and gives us a factual identity."