http://www.sciencealert.com.au/news/20132404-24299.html

Ancient DNA recovered from a series of skeletons in central Germany up to 7500 years old has been used to reconstruct the first detailed genetic history of modern Europe.

“The record of this maternally inherited genetic group, called Haplogroup H, shows that the first farmers in Central Europe resulted from a wholesale cultural and genetic input via migration, beginning in Turkey and the Near East where farming originated and arriving in Germany around 7500 years ago,” says joint lead author Dr Paul Brotherton, formerly at ACAD and now at the University of Huddersfield, UK.
ACAD Director Professor Alan Cooper says: “What is intriguing is that the genetic markers of this first pan-European culture, which was clearly very successful, were then suddenly replaced around 4500 years ago, and we don’t know why. Something major happened, and the hunt is now on to find out what that was.”
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Love a decent mystery.

>ACAD Director Professor Alan Cooper says: “What is intriguing is that the genetic markers of this first pan-European culture, which was clearly very successful, were then suddenly replaced around 4500 years ago, and we don’t know why. Something major happened, and the hunt is now on to find out what that was.”

Presumably the peoples of northen Europe who were not hitherto farmers, took up farming. And chased many of the southerners back to southern Europe and the near East etc.

Abstract and figures in: http://www.nature.com/ncomms/journal/v4/n4/full/ncomms2656.html
or full article if you have subscription.

“Haplogroup H dominates present-day Western European mitochondrial DNA variability (>40%), yet was less common (~19%) among Early Neolithic farmers (~5450 BC) and virtually absent in Mesolithic hunter-gatherers. Here we investigate this major component of the maternal population history of modern Europeans and sequence 39 complete haplogroup H mitochondrial genomes from ancient human remains. We then compare this ‘real-time’ genetic data with cultural changes taking place between the Early Neolithic (~5450 BC) and Bronze Age (~2200 BC) in Central Europe. Our results reveal that the current diversity and distribution of haplogroup H were largely established by the Mid Neolithic (~4000 BC). …”

Note that mitochondrial DNA is the easiest to sequence from fossils because it is present in much higher quantity than nuclear DNA. Going from past studies, analysis of full genomes or even Y chromosome would tell a different story.