Are the Scots-Irish Genetically Irish? What the DNA Actually Says
Traced in the DNA
4,657 views
In 1718, three hundred and nineteen Ulster Presbyterians signed a petition to come to America. Seventy-one years later, an American geographer wrote that their people were "more properly called Irish." Ask the internet today and you get the same answer. Ask science and you get three answers that disagree: the Irish DNA Atlas, the Uí Néill father's line, and AncestryDNA's map of 770,000 American genomes.
The Scots-Irish are a stack of arrivals. Tonight we take them oldest first and measure every layer, from the hunters of Mount Sandel to the families who walked down the Great Wagon Road. By the end you will know which answer fits your question, why the first people ever called "Scotch-Irish" were not Presbyterians, and the fourth answer nobody has measured yet.
📍 Layer 1: Mount Sandel and the first farmers (Ballynahatty, c. 3300 BC)
📍 Layer 2: the Beaker people and the Bronze Age men of Rathlin Island
📍 Layer 3: Were the Scots Irish? Picts, Gaels and the Dál Riata myth
📍 Layer 4: the Angles, and where Scots speech came from
📍 Layer 5: the Vikings, measured (more names than genes)
📍 Layer 6: the Normans who became Scots, and how Stewart got to Antrim
📍 Layer 7: the riding names, and the Grahams a king shipped to Ireland
📍 Layer 8: the Plantation, 1606–1690s, and its four-hundred-year signal
📍 Layer 9: the first "Scotch-Irish" (1573), the gallowglass and Donegal
📍 Layer 10: the crossing, 1717–1775, and the Appalachian clusters
Tell me in the comments your surname, your county on either side of the water, and the decade your family left. I read every one.
🔎 TRACE YOUR SURNAME: https://dnaorigin.org
Type in your surname and it does the research for you: where the name was first written down in Scotland or Ulster, whether it is a Lowland, Border or Gaelic name, which plantation estate or parish it was recorded on, when the family crossed to America, and the county where they first took land. Or scan the QR code on screen.
Sources used in this episode:
Gilbert E. et al. (2017) The Irish DNA Atlas: revealing fine-scale population structure and history within Ireland. Scientific Reports.
Gilbert E. et al. (2019) The genetic landscape of Scotland and the Isles. PNAS.
Byrne R.P. et al. (2018) Insular Celtic population structure and genomic footprints of migration. PLoS Genetics 14(1):e1007152.
Moore L.T. et al. (2006) A Y-chromosome signature of hegemony in Gaelic Ireland. American Journal of Human Genetics.
Han E. et al. (2017) Clustering of 770,000 genomes reveals post-colonial population structure of North America. Nature Communications 8:14238.
Cassidy L.M. et al. (2016) Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome. PNAS.
Olalde I. et al. (2018) The Beaker phenomenon and the genomic transformation of northwest Europe. Nature.
Morez A. et al. (2023) Imputed genomes and haplotype-based analyses of the Picts of early medieval Scotland. PLoS Genetics.
Campbell E. (2001) Were the Scots Irish? Antiquity 75(288):285–292.
McEvoy B., Brady C., Moore L.T., Bradley D.G. (2006) The scale and nature of Viking settlement in Ireland from Y-chromosome admixture analysis. European Journal of Human Genetics.
Matheson R.E. (1894) Special Report on Surnames in Ireland (births index of 1890). General Register Office, Dublin.
Hunter R.J. (ed.) (2012) Men and Arms: The Ulster Settlers, c. 1630. Ulster Historical Foundation.
Petition of 26 March 1718 to Governor Samuel Shute (see Ulster Historical Foundation, The 1718 Migration).
Morse J. (1789) The American Geography.
Letter of Elizabeth I, 14 April 1573 (Sorley Boy MacDonnell, "the Scotch-Irish race").
Griffin P. (2001) The People with No Name. Princeton University Press.
Fischer D.H. (1989) Albion's Seed: Four British Folkways in America. Oxford University Press.
Leyburn J.G. (1962) The Scotch-Irish: A Social History. University of North Carolina Press.
Chalkley L. (1912–13) Chronicles of the Scotch-Irish Settlement in Virginia.
U.S. Census Bureau, American Community Survey 2017 (ancestry).
Harney et al. (2026) ancient genomes of the Chapel Field colonists, St. Mary's City, Maryland. Current Biology.
8 Comments
Scots/Irish are basically the folk from,whats now known as Northern Ireland (most of it used to be in the Irish provence called Ulster)!
A mixture of Scots/English/Irish people who went over to Canada/USA all those years ago!
Also, not told are the people who inhabited Scotland before the Scottish. They were Brythonic speaking, some of their names were known because they were documented by the Britons in the West in Cymru, such as those in Rhedeg, Alt Clut, Din Eidyn, Y Gododdin.
The Picts were also Brythonic speaking, a collective of tribes, not one people, this proven by DNA, whose were largely unaffected by the Roman Empire, this because of the terrain they lived in. In fact, the word Caled in Caledonia in Pictland literally means hard or tough in Welsh, and likely refers to the landscape being mountainous.
The word Caled is also the root of King Arthur's sword, Excalibur, a name corrupted from the old Welsh by the Norman French scribes for the mythical sword, Caledfwlch meaning, Hard Cleaver.
In Welsh tradition Cunedda and other tribes from the Old North (Hen Ogledd) travelled south to Cymru to found the Kingdom of Gwynedd.
Are the Scots-Irish Genetically Irish? What the DNA Actually Says
Traced in the DNA
4,657 views
In 1718, three hundred and nineteen Ulster Presbyterians signed a petition to come to America. Seventy-one years later, an American geographer wrote that their people were "more properly called Irish." Ask the internet today and you get the same answer. Ask science and you get three answers that disagree: the Irish DNA Atlas, the Uí Néill father's line, and AncestryDNA's map of 770,000 American genomes.
The Scots-Irish are a stack of arrivals. Tonight we take them oldest first and measure every layer, from the hunters of Mount Sandel to the families who walked down the Great Wagon Road. By the end you will know which answer fits your question, why the first people ever called "Scotch-Irish" were not Presbyterians, and the fourth answer nobody has measured yet.
📍 Layer 1: Mount Sandel and the first farmers (Ballynahatty, c. 3300 BC)
📍 Layer 2: the Beaker people and the Bronze Age men of Rathlin Island
📍 Layer 3: Were the Scots Irish? Picts, Gaels and the Dál Riata myth
📍 Layer 4: the Angles, and where Scots speech came from
📍 Layer 5: the Vikings, measured (more names than genes)
📍 Layer 6: the Normans who became Scots, and how Stewart got to Antrim
📍 Layer 7: the riding names, and the Grahams a king shipped to Ireland
📍 Layer 8: the Plantation, 1606–1690s, and its four-hundred-year signal
📍 Layer 9: the first "Scotch-Irish" (1573), the gallowglass and Donegal
📍 Layer 10: the crossing, 1717–1775, and the Appalachian clusters
Tell me in the comments your surname, your county on either side of the water, and the decade your family left. I read every one.
🔎 TRACE YOUR SURNAME: https://dnaorigin.org
Type in your surname and it does the research for you: where the name was first written down in Scotland or Ulster, whether it is a Lowland, Border or Gaelic name, which plantation estate or parish it was recorded on, when the family crossed to America, and the county where they first took land. Or scan the QR code on screen.
Sources used in this episode:
Gilbert E. et al. (2017) The Irish DNA Atlas: revealing fine-scale population structure and history within Ireland. Scientific Reports.
Gilbert E. et al. (2019) The genetic landscape of Scotland and the Isles. PNAS.
Byrne R.P. et al. (2018) Insular Celtic population structure and genomic footprints of migration. PLoS Genetics 14(1):e1007152.
Moore L.T. et al. (2006) A Y-chromosome signature of hegemony in Gaelic Ireland. American Journal of Human Genetics.
Han E. et al. (2017) Clustering of 770,000 genomes reveals post-colonial population structure of North America. Nature Communications 8:14238.
Cassidy L.M. et al. (2016) Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome. PNAS.
Olalde I. et al. (2018) The Beaker phenomenon and the genomic transformation of northwest Europe. Nature.
Morez A. et al. (2023) Imputed genomes and haplotype-based analyses of the Picts of early medieval Scotland. PLoS Genetics.
Campbell E. (2001) Were the Scots Irish? Antiquity 75(288):285–292.
McEvoy B., Brady C., Moore L.T., Bradley D.G. (2006) The scale and nature of Viking settlement in Ireland from Y-chromosome admixture analysis. European Journal of Human Genetics.
Matheson R.E. (1894) Special Report on Surnames in Ireland (births index of 1890). General Register Office, Dublin.
Hunter R.J. (ed.) (2012) Men and Arms: The Ulster Settlers, c. 1630. Ulster Historical Foundation.
Petition of 26 March 1718 to Governor Samuel Shute (see Ulster Historical Foundation, The 1718 Migration).
Morse J. (1789) The American Geography.
Letter of Elizabeth I, 14 April 1573 (Sorley Boy MacDonnell, "the Scotch-Irish race").
Griffin P. (2001) The People with No Name. Princeton University Press.
Fischer D.H. (1989) Albion's Seed: Four British Folkways in America. Oxford University Press.
Leyburn J.G. (1962) The Scotch-Irish: A Social History. University of North Carolina Press.
Chalkley L. (1912–13) Chronicles of the Scotch-Irish Settlement in Virginia.
U.S. Census Bureau, American Community Survey 2017 (ancestry).
Harney et al. (2026) ancient genomes of the Chapel Field colonists, St. Mary's City, Maryland. Current Biology.