Europe’s first farmers replaced hunter-gatherers
4 September 2009
Analysis of ancient DNA from skeletons suggests that Europe’s first farmers were not the descendants of the people who settled in the area after the retreat of the ice sheets.
Instead, the early farmers probably migrated into major areas of central and Eastern Europe about 7,500 years ago, bringing domesticated plants and animals with them, according to new research from Mainz University, UCL and the University of Cambridge, published online in Science.
The researchers analysed DNA from hunter-gatherer and early farmer burials, and compared those to each other and to the DNA of modern Europeans. They conclude that there is little evidence of a direct genetic link between the hunter-gatherers and the early farmers, and that 82% of the types of mtDNA found in the hunter-gatherers are relatively rare in central Europeans today.
For more than a century, archaeologists, anthropologists, linguists, and more recently, geneticists, have argued about the identity of the ancestors of Europeans living today. They have established that people lived in Europe before and after the last big ice age, and managed to survive by hunting and gathering. They also know that farming spread into Europe from the Near East over the last 9,000 years, thereby increasing the amount of food that can be produced by as much as 100-fold. But the extent to which modern Europeans are descended from either of those two groups has eluded scientists despite many attempts to answer this question.
Now, a team from Mainz University in Germany, together with researchers from UCL and Cambridge, have found that the first farmers in central and northern Europe could not have been the descendents of the hunter-gatherers that came before them. But even more surprisingly, they also found that modern Europeans couldn’t solely be the descendants of either the hunter-gatherer alone, or the first farmers alone, and are also unlikely to be a mixture of just those two groups.
“This is really odd”, said Professor Mark Thomas, UCL Genetics, Evolution & Environment and co-author of the study. “For more than a century the debate has centred around how much we are the descendants of European hunter-gatherers and how much the descendants of Europe’s early farmers. For the first time, we are now able to directly compare the genes of these Stone Age Europeans, and what we find is that some DNA types just aren’t there – despite being common in Europeans today.”
Humans arrived in Europe 45,000 years ago and replaced the Neanderthals. From that period on, European hunter-gatherers experienced lots of climatic changes, including the last Ice Age. After the end of the Ice Age, some 11,000 years ago, the hunter-gatherer lifestyle survived for a couple of thousand years, but was then gradually replaced by agriculture. The question was whether this change in lifestyle from hunter-gatherer to farmer was brought to Europe by new people, or whether only the idea of farming had spread. The new results from the Mainz-led team seem to resolve much of this long standing debate.
“Our analysis shows that there is no direct continuity between hunter-gatherers and farmers in Central Europe,” says Prof Joachim Burger. “As the hunter-gatherers were there first, the farmers must have immigrated into the area.”
The study identifies the Carpathian Basin as the origin for early Central European farmers. “It seems that farmers of the Linearbandkeramik culture immigrated from what is modern day Hungary around 7,500 years ago into Central Europe, initially without mixing with local hunter gatherers,” says Barbara Bramanti, first author of the study. “This is surprising, because there were cultural contacts between the locals and the immigrants, but, it appears, no genetic exchange of women.”
The new study confirms what Joachim Burger´s team showed in 2005; that the first farmers were not the direct ancestors of modern European. Burger says “We are still searching for those remaining components of modern European ancestry. European hunter-gatherers and early farmers alone are not enough. But new ancient DNA data from later periods in European prehistory may shed also light on this in the future.”
Media Contact: Ruth Howells