 What's the Chengis Khan effect and what has it got to do with Ireland and Scotland? In the early 2000s researchers from Oxford University found a Y chromosome with a particular fingerprint that was widespread across Asia, which is quite unusual considering that Y chromosomes are generally localised. The explanation for this was that researchers had stumbled across the Y chromosome from the Great Khan of the Mongol Empire. Chengis Khan, who ruled during the 13th century. On further inspection it was found that around 8% of men in Mongolia had this Y chromosome and around 60 million men across Asia had Chengis Khan's Y chromosome. This is hardly surprising given that after the Mongols had conquered the territory they usually killed all men and brought the attractive women to Chengis Khan. This reproductive dominance was dubbed the Chengis Khan effect but what has any of this got to do with Ireland or Scotland? In Brian Sykes, the late professor of human genetics at Oxford University, book on Saxons, Vikings and Celts, the genetic roots of Britain and Ireland. He details how the Chengis Khan effect could be at work in Ireland and Scotland, stemming from two key individuals, Nile of the Nine Hostages and the summer lads of the Isles. Nile of the Nine Hostages was a semi-mythical High King of Ireland who lived around the 4th and 5th centuries A.D. Famous for potentially bringing the man that would become St Patrick to Ireland initially as a captive. Y chromosome tests from Ireland have shown that Nile's genetic fingerprint is present in large numbers of men with O'Neill clan surnames such as Gallacher, Boyle, Docherty, O'Connor, Bradley as well as O'Neill. In the Northwest of Ireland, around a quarter to a fifth of the male population has this particular Y chromosome signature. An equivalent is found in Scotland in the form of Summer Lade, a North Scalic Lord of the 12th century who established the Kingdom of Argyll and the Isles and who is credited with expelling the Vikings from Western Scotland. Summer Lades Y chromosome is widespread across the Highlands and Islands of Scotland and those of those descents overseas. Sykes estimates that around a quarter of McDonald's, a third of McDougals and 40% of McAllisters are direct paternal descendants of Summer Lade. Globally it is estimated that around 200,000 men have Summer Lades Y chromosome. As we've seen the changes can affect is present well beyond Mongolia. Please let me know your thoughts below. Thanks for watching. If you would like to support this work through Patreon buy me a coffee.com or make a donation through PayPal please do so via the links in the description below. Please remember to subscribe and hit the bell and I'll speak to you soon.