A new study examining DNA shows that 4,000 years ago, a huge wave of immigrants entered Ireland from a seemingly unlikely place.

The Middle East and the Black Sea region is the source of those immigrants, the study claims according to a Daily Mail report.

Celtic people actually have very distinct traits making them very easy to trace, even as far back as 4,000 years ago, and scientists from Queens University Belfast and Trinity College Dublin examined four individuals found in Ireland to come to their conclusions.

The Celtic people were likely established 4,000 years ago as people swept in from the Black Sea and Middle East areas seeking good land to farm.

The researchers made this determination by looking at ancient genomes from four people to identify the genetic shift. The adoption of agriculture appeared to make Ireland an ideal settling point for many waves of immigrants that resulted in a huge shift in genetics from the population on the island.

One of the individuals who was examined was likely a female Neolithic farmer who had lived in the Belfast area 5,200 years ago. The researchers also examined three men found in County Down, believed to be from the Bronze Age 4,000 years ago.

The woman’s genome appeared to have a mix of genes from both early hunter gatherer DNA and Near East farmers.

The other three who were examined at a later time seemed to have a much closer match to the genetic traits in modern Irish people. They had blue eyes as well as the most common form of the Y chromosome found in Ireland.

These genetic traits were likely brought from the Black Sea region, which today includes Ukraine, Russia, and Georgia.