More details on the beginnings of agriculture. Archeologists have uncovered several villages in the Middle East where their findings indicate very early agricultural practices and so the development of permanent settlements. One village, Ohalo II on the banks of the Sea of Galilee, had over 150,000 charred seeds and nuts of various sorts soon to be domesticated if they had not been already. These dated from 23,000 years ago and farming is generally dated back to 11,000 years ago, so this suggests that humans domesticated plants over a long period of time. Another one of these villages, Ain Ghazal in central Jordan, has yielded ample evidence from 10,000 years ago of agriculture using both domesticated plants and animals, clay figurines used ritually and burial practices. The scientists have also recovered from there and several other villages in the fertile crescent human DNA. Their analysis shows that these early farmers spread out west and east from India to Ireland but not all at once. And different farming populations within that area were very different genetically, as different as Europeans and Chinese are today, and that these differences were maintained for thousands of years.
So this archeological evidence uncovering the beginnings of agriculture also shows something of group dynamics as we went from tribes of hunter-gatherers with some trade to cities with much trade over a roughly 20,000 year period, say from 25,000 years ago to 5,000 years ago. We know that people had been trading for a long time before that and traveling long distances to do so, or to settle in a new place, and that this led to some interbreeding, say between modern humans and Neandertals or Denisovans, with enough genetic exchange that we can find its evidence in today’s population. With these studies it looks like the initial phase of agriculture was marked by some practices limiting marriage outside the local group. This went on from 11,000 (at the latest) to 8,000 years ago and then inter-breeding exploded and these populations engaged with each other and across southern Asia and into all of Europe. The groups of hunter-gatherers were slowly assimilated into the growing population of agriculturalists through breeding more than by their adopting the new technologies for producing food.
I really like this story as it shows the gradual accretion of scientific knowledge and its correction of hypotheses by additional findings. (Check out the link to NYT story: http://www.nytimes.com/2016/10/18/science/ancient-farmers-archaeology-dna.html). I do not claim to understand very well the ability of geneticists to detect these changes over time but it is at this point a respected methodology. The emerging picture of agriculture starting in several locations contemporaneously as people “played around” (read ‘experimented’) with different seeds and nuts stock and with domesticating animals such as goats is fascinating. Even more so is that these groups were insular for a good 3,000 years; they may have traded but they did not inter-marry. They may not have traveled afar as much when they began to construct more permanent villages and farmed. Traders may have then become a distinct profession and limited in numbers. This all implies a cultural belief involving in-group/out-group dynamics; we see forms of this in wolves, apes, hunter-gatherers recent and ancient, and modern humans. Given this dynamic in the middle Eastern origins in agriculture, it is no coincidence, then, that one of the primary groups to emerge in that area, the Jewish people, have maintained that dynamic control of inter-marriage even to this day to some extent.
And then we have the stories not of human stocks but of seed stocks investigated by Nikolai Vavilov as he brilliantly and presciently researched in the first half of the 20th century (before he starved to death in Stalin’s prison because he did not bow down to Lysenko’s pseudo-science) the geographical origins of various food crops, but enough for now. It is time to travel on.