 What is the ancient genetic history of Britain and Ireland? In one of my previous videos on the genetic history of Britain, I looked at the impact of migrations and invasions, from the likes of the Vikings, the Normans, the Romans and the Anglo-Saxons. But what about the migrations and invasions that took place thousands of years prior to this? If we were to go way back for a second, species of humans, Homo neanderthal lensis and Homo hydel burgensis were in Britain from 800,000 years ago, living by hunting wild animals and gathering plant foods. Our species, Homo sapiens, are thought to have entered Britain around 44,000 years ago, during the last Ice Age, which itself existed from around 115,000 years ago to 11,700 years ago. Rapid changes of climate caused humans to move in and out of Britain during the last Ice Age. The ice was at its greatest extent during the last glacial maximum, a period during the last Ice Age where the glaciers, the ice was essentially at its greatest point, around 26,000 to 20,000 years ago. At this time, Britain was pretty much uninhabitable. Somewhere around 12,000 years ago, after the younger dryus period, which was a brief return to glacial conditions, the ice gradually melted and began to rapidly melt. Sea levels rose around this time as well, given the melting of ice. But what are some of the main migrations into Britain and Ireland in the 10,000 years or so between the end of the Ice Age and the Romans invading Britain, beginning with Julius Caesar's invasions or Britain in the 1st century BC? This 10,000-year stretch between the Ice Age and the Romans, what were the main migrations that had a profound impact on the genetic makeup of Britain and Ireland today? Small groups of Homo sapiens would have started moving back into Britain and Ireland after the last Ice Age, quite soon after the Ice Age. And one of the main mechanisms by which they would have crossed from Europe into Britain was through Doggerland, which was a land bridge that connected Britain and continental Europe, and was swallowed up by the sea around 8,000 years ago or so. When Doggerland was swallowed up by the sea, Britain became an island as we know it today. Very early settlers of Britain moved across from West Germany and the Atlantic coast of Europe, and these first settlers spread across England, Scotland, Wales and Ireland. What is interesting is that after these earliest settlers of Britain and Ireland arrived in these lands, future migrations and invasions into these lands, would have affected the populations of England, Scotland and Ireland far more than they would have affected Wales. Wales, therefore, is the most genetically similar to the earliest settlers of Britain and Ireland. A little later, between 6,000 to 3,000 years ago, or around 4000 BC to around 1000 BC, as the people of the British Isles study found, there was a large movement of people from Northern France into England and Scotland, at about the same time that agriculture began to be widespread. The genetic study revealed a pattern of DNA dated to around this time that is shared by people now living in Northern France and those in England, the North of Ireland, as only the North of Ireland was studied in this particular study, and also Scotland, but none of those in Wales. The study noted that these people may have included the first farmers at the start of the Neolithic age, or there may have been some of the beaker people who introduced characteristic, decorated pottery, developed copper working and traded metal with other parts of Europe. This leads nicely on to another people that had a profound impact on the ancient genetic makeup of Britain and Ireland. They are known as beaker people. I made a full video on the bell beaker culture and beaker people in general, that I will link above and you can watch in a little more detail. But these were fascinating people. They arose around 5,000 years ago in Iberia, present-day Spain and Portugal, and they soon spread across much of Europe and into Britain. They were known for bell-shaped pottery vessels, and that is how they get their name. They were often decorated in really nice patterns, in kind of tooth-snap patterns. A 2018 study published in Nature found that the beaker people replaced 90% of Britain's gene pool in only a few hundred years and introduced high levels of step-related ancestry into Britain. It is clear that the bell beaker people are profound ancient ancestors of people in both Britain and Ireland. Another study from 2019 looks specifically at how farming was introduced into Britain. Farming in general was introduced into Britain and Ireland somewhere around 4,000 BC or around 6,000 years ago, and most studies have now shown that this was due to a large migration from people from Europe into Britain and Ireland. There was initially a bit of a debate about whether hunter-gallarers, like an indigenous hunter-gallarers of Britain and Ireland, played a significant role themselves in developing and evolving into a more agricultural society. But a lot of studies now, although there is still some debate, seem to point to a migration of people coming from Europe with the skills, the knowledge, the technology and brought farming with them, as opposed to it being an indigenous feature that developed within Britain and Ireland itself. There was some mixture there, but there was a profound migration into Britain and Ireland that brought farming with them. These farmers are thought to have travelled along the Mediterranean route, but they probably originated around a G&C, a sea which sits between Turkey and Greece today. Another study that looks specifically at Ireland found similar results, i.e. that farming was introduced by migration from European farmers from the Near East region, essentially modern Turkey Middle East region. The found us by analysing the genetic ancestry of an Irish female farmer from a megalithic tomb near Belfast dated just over 3000 BC. This study in general analysed three Bronze Age individuals found in Ireland, and the research has noted the presence of step-related ancestry in all three individuals. The authors write that it is clear that the great wave of genomic change which spet from above the Black Sea into Europe around 3000 BC washed all the way to the northeast shore of its most westerly island. At present, the beaker culture is the most probable archaeological vector of this step 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 may estimate at roughly a third of Irish Bronze Age ancestry opens the possibility of accompanying language change, perhaps the first introduction of Indo-European language ancestral to Irish. It is interesting that lots of studies that looked at Britain and those that looked specifically at Ireland seemed to find quite similar results, that there was large migrations from Europe into Britain, and they also reached Ireland. These migrations did not just stop at Britain, they made the leap to Ireland to a large extent. Another study from 2021 found that there was another sizable movement of people from continental Europe into Britain between 1400 and 870 BC. The study estimated that around half the ancestry of later populations in England and Wales comes from these migrants. There are numerous interesting aspects of this study. First up is the fact that many point to this migration and the timing of this migration is potentially being a vector by which Celtic limeges were introduced into Britain and Ireland. Probably fraught from south-western France or southern France. The study pointed to, if memory serves at least. This interesting feature, there is a debate about how Celtic limeges were introduced into Britain and Ireland, or if they were introduced. Some argue like Barry Cunliff, who's the Emirates Professor of European Archaeology at the University of Oxford, that potentially Celtic limeges originated as a lingua franca, essentially a trading language in the Atlantic zone. And basically originated, the proto-Celtic limeg anyway originated in Britain and Ireland, and then dispersed from there, and then moved into Europe easterly. Where is the other argument? Essentially argues that Celtic limeges originated in central-western Europe, and then migrated west into Britain and Ireland. There is obviously a debate and it's not like the debate is closed at all. This study was obviously interesting, however, the fact it noted that there was a migration around the time that would make sense for Celtic limeges to be introduced, if they were indeed introduced, from Europe into Britain and Ireland. Another interesting point to note is that lack taste tolerance, essentially the ability to digest milk, seemed to spike the tolerance of people that were able to digest milk in Britain and Ireland, seemed to increase rapidly around this time of the migration. Potentially signalling that these migrations had their part to play in this, although it is debated by experts exactly why this happened, exactly why more people were able to digest milk around this general timescale and the period after this timescale. I am actually going to explore this in a little more detail as there seems to be a relationship between ancient Celtic cultures and the ability to digest milk, but like I say, I'll explore in more detail in a future video. Obviously, as a quick caveat, the further back you go in time, the more complicated things get and the harder it is to trace migrations and the increase there is an increase in the margin of error, just given the timescales we're talking about. So bear that in mind given this research, but hopefully I've given a good overview of the ancient history, genetic history of Britain and Ireland. But what about the genetic history of Britain in the north of Ireland in more recent times? The Romans, the Vikings, the Anglo-Saxons and the Normans. What impact did they have on the genetic makeup of Britain in the north of Ireland? To find out, please click here. Thanks for watching. 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