Where did all the farmers come from?
Farming and cities seem very much the norm now but in the grand scheme they're actually very recent developments. Modern humans have been around for about 200,000 years and farming has only been with us for the last ten thousand. Farming is a key threshold in human development because once you start farming a piece of land you can support a much greater number of people in a certain area than you would with most hunting and gathering. Although, there are some places in the world where land and sea are so abundant in food you don't need to farm to support lots of people (but that's another story...).
The Near East (that includes Iraq, Iran and Syria) is one place where farming is thought to have originated and later spread through Europe. And there's been something of an argument between academics as to how the spread took place and how it happened so quickly. Some people have argued that farming techniques were rather peacefully communicated through neighbouring populations and that hunter-gatherers gradually gave up their lifestyle and language in favour of the farmers'. But some people argue that the farmers were a specific group of people who out-competed and eventually replaced the native hunter-gatherers in Europe.
Now Barbara Bramanti and her team have taken mitchondrial DNA (mtDNA) samples from three groups. Publishing in the journal Science this week,they took mtDNA from a group of 11,000 year-old hunter-gatherers and mtDNA from some of the earliest farmers. What they found was that these two groups were too distinct to be related. So they then looked at how ancient hunter-gatherers might be related to modern-day Europeans and again, the relationship was almost non-existent.
But it does seem that Central Europeans are descended, at least in part, from these early farmers. So what we can draw from this is that at the end of the last ice age, some people developed farming and they moved most the way across Europe, quite likely displacing the hunter-gatherers. And they think these farmers originated in an area around modern day Slovakia or Hungary but the researchers say they need to do a few more DNA studies to be sure.
So understanding when and why we started farming can tell us something about how we came to live in the cities we do today and also how farming might affect communities across the world which do practise hunter-gatherer lifestyles, e.g. the San in Namibia or Aeta in the Philippines.