 Considering that nearly half the world's population speaks a language that's part of the Indo-European language family, from Irish and Scottish Gaelic to Sanskrit and India, what do we know about the genetic legacy left by the massive waves of Indo-European migration? Well we can see the genetic fingerprints of the Indo-Europeans right across Eurasia, and it may partly explain why there are so many origin stories in the likes of Scotland and Ireland that discuss cultures from the steppe, an area just north of the Black Sea and to the east. The origins of the Indo-European seems to be a mixture of both Anatolia and the Pontic Caspian steppe, with various cultures over the centuries and millennia spreading Indo-European traits at outwards. The presence of steppe-related ancestry in so many parts of Eurasia is actually quite astonishing, and it's considered a strong marker of the legacy of these Indo-European migrations. Three cultures in particular were important in this spread, and they're important to understand before we move on to document some of the recent findings from genetic research. The Yamnaya culture, also known as the Pit Grave culture, was one, which existed from around 3300 to 2600 BC and the Pontic Caspian steppe. The rapid spread of the Yamnaya culture across Eurasia has led many to argue that this might have been quite a violent event, with the Yamnaya people potentially committing genocide against the native peoples they largely went on to replace, but that's a story for another time. Second up is a connected culture known as the Corded Ware culture, a culture that existed from around 3000 BC to around 2350 BC, and occupied a massive area, from a contact zone with the Yamnaya culture to stretching right across a large part of central and western Europe, and even into parts of Scandinavia. Thirdly there was the Bell Beaker culture, which existed from around 2800 BC to around 1800 BC, and occupied an area much further west, and western Europe, Britain and Ireland. Now a study from 2015 looked at this massive migration from the steppe across Europe, and found that western and eastern Europe came into contact around 4500 years ago, as the late Neolithic Corded Ware people from Germany who traced about 75% of their ancestry to the Yamnaya, documenting a massive migration into the heartland of Europe from its eastern periphery. This steppe ancestry persisted in all sampled central Europeans until at least 3000 years ago, and is ubiquitous in present-day Europeans. These results provide support for a steppe origin of at least some of the Indo-European languages of Europe. There are particular genetic markers that are associated with the Indo-Europeans, namely haplogrps R1A and R1B, which would have expanded from the Pontic Steppe, and which are common markers across Eurasia, with R1B particularly common in western Europe. This table shows a breakdown of R1B by region. It is very common in western Europe and other parts of Europe, but also found in people from Russia, South Asia and even parts of Africa. What is quite astonishing is how far the steppe ancestry spread across Europe. Ireland for instance is pretty far from the steppe area, and you wouldn't necessarily think that there would be strong steppe ancestry in Ireland, well think again. A 2016 study from Ireland looked at three Bronze Age males from Rathland Island, a tiny island off the coast of the north of Ireland, who lived between 2000 and 26 BC and around 1500 BC. The study found that each Bronze Age sample that were all male exhibits the Bronze Age associated with chromosome lineage, R1B M269, the appearance of which has been strongly linked with the steppe incursion into central Europe. Thus it is clear that the great wave of genomic change which swept across from above the Black Sea into Europe around 3000 BC washed it all the way to the northeast shore of its most westerly island. At present, the beaker culture is the most probable archaeological vector of the steppe ancestry into Ireland from the continent, although further sampling from beaker burials across western Europe will be necessary to confirm this. The extent of this change, which we estimate are roughly a third of Irish Bronze Age ancestry, opens the possibility of associated lineage change, perhaps the first introduction of the Indo-European lineage ancestral to Irish. If we look at other parts of Europe, we see a similar pattern. A 2021 study, for instance, looked at the genetics of Bronze Age individuals from Greece and the Aegean Sea area. The study found by the Middle Bronze Age around 4000-4600 years ago. Individuals from the Northern Aegean were considerably different compared to those of the Early Bronze Age. These individuals shared half their ancestry with people from the Pontic Caspian steppe, a large geographical region stretching between the Danube and the Ural rivers and north of the Black Sea, and were highly similar to present-day Greeks. The findings suggest that migration waves from herders from the Pontic Caspian steppe, or populations north of the Aegean, that bear Pontic Caspian steppe like ancestry. These potential migration waves all predate the appearance of the earliest documented form of Greek, supporting theories explaining the emergence of proto-Greek and the evolution of the Indo-European limeges in either Anatolia or the Pontic Caspian steppe region. As I've mentioned a few times now, we also know that there's a large degree of steppe-related ancestry that was introduced into Britain, as the 2018 study found. The spread of the beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain's gene pool within a few hundred years, continuing the East-West expansion that brought steppe-related ancestry into central and northern Europe over the previous centuries. Now the steppe ancestry didn't just spread west and south however, but east as well, as a 2019 study that looked at South Asia found. The primary ancestral population of modern South Asians is a mixture of people related to early Holocene populations of Iran and South Asia that we detect in outlier individuals from two sites in cultural contact with the Indus Valley Civilisation, making it plausible that it was characteristic of the Indus Valley Civilisation. After the civilisation's decline, this population mixed with Northwestern groups with steppe ancestry to form the ancestral North Indians, and also mixed with Southeastern groups to form the ancestral South Indians, whose direct descendants today live in tribal groups in southern India. Mixtures of these two post-Indus Valley Civilisation groups, the ancestral North Indians and the ancestral South Indians, drive the main ingredient of genetic variation in South Asia today. Now as we have seen, the spread of Indo-European cultures led an ancient genetic layer in many of the peoples across Eurasia, and is a clear genetic fingerprint of the Indo-European migrations. To find out more about the Indo-Europeans, the connections in the limeges and many other facts, please click here. Thanks for watching, please subscribe and hit the bell for ways to support the wellbeing in the description below. Thanks again for watching and I'll see you next time.