For quite a number of decades, it has been apparent that agriculture was first invented in the "Fertile Crescent" of the Middle East, then spread into Europe. But that raised the question of how agriculture spread: did Middle Easterners colonize Europe or did existing European hunter-gatherers pick up Middle Eastern techniques? A couple of decades or so ago, geneticists entered this debate. L.L. Cavalli-Sforza argued that most Europeans today are descended from Middle Eastern farmers. Bryan Sykes responded that most Europeans are descended from indigenous hunter-gatherers who switched to farming.

The latest view is that Cavalli-Sforza was even more right than he claimed. Matthias Schultz writes in Der Spiegel in "How Middle Eastern Milk Drinkers Conquered Europe:"

At around 5300 BC, everyone in Central Europe was suddenly farming and raising livestock. The members of the Linear Pottery culture kept cows in wooden pens, used rubbing stones and harvested grain. Within less than 300 years, the sedentary lifestyle had spread to the Paris basin.

The reasons behind the rapid shift have long been a mystery. Was it an idea that spread through Central Europe at the time, or an entire people?

Peaceful Cooperation or Invasion?

Many academics felt that the latter was inconceivable. Agriculture was invented in the Middle East, but many researchers found it hard to believe that people from that part of the world would have embarked on an endless march across the Bosporus and into the north.

Jens L??ning, a German archaeologist who specializes in the prehistoric period, was influential in establishing the conventional wisdom on the developments, namely that a small group of immigrants inducted the established inhabitants of Central Europe into sowing and milking with "missionary zeal." The new knowledge was then quickly passed on to others. This process continued at a swift pace, in a spirit of "peaceful cooperation," according to L??ning.

But now doubts are being raised on that explanation. New excavations in Turkey, as well as genetic analyses of domestic animals and Stone Age skeletons, paint a completely different picture:

• At around 7000 BC, a mass migration of farmers began from the Middle East to Europe.
• These ancient farmers brought along domesticated cattle and pigs.
• There was no interbreeding between the intruders and the original population.

Mutated for Milk

The new settlers also had something of a miracle food at their disposal. They produced fresh milk, which, as a result of a genetic mutation, they were soon able to drink in large quantities. The result was that the population of farmers grew and grew.

These striking insights come from biologists and chemists. In a barrage of articles in professional journals like Nature and BMC Evolutionary Biology, they have turned many of the prevailing views upside down over the course of the last three years.

There's a good accompanying graphical map here.

Of course, all this raises even more questions, such as in regard to the recently surmised Neanderthal introgression

Having seen opinion shift several times on this topic over the last decade and a half, I look forward to future developments.

This lactose tolerant-centric view of the pre-history of Europe may provide some posthumous vindication to Raymond D. Crotty, a failed Irish dairy farmer turned economist, who emphasized the importance of the mutation to facilitate dairy farming as crucial to the dense populating of Northern Europe.