Ancient DNA sheds light on spread of European farming

Analyzing DNA from four ancient skeletons and comparing it with thousands of genetic samples from living humans, a group of Scandinavian scientists reported that agriculture initially spread through Europe because farmers expanded their territory northward, not because the more primitive foragers already living there adopted it on their own.
The genetic profiles of three Neolithic hunter-gatherers and one farmer who lived in the same region of modern-day Sweden about 5,000 years ago were quite different — a fact that could help resolve a decades-old battle among archaeologists over the origins of European agriculture, said study leader Mattias Jakobsson, a population geneticist at Uppsala University in Sweden.