Professor Gordon Hillman, at University College London, has spent over 20 years investigating the remains of ancient food plants at a unique site at Abu Hureyra, in the middle Euphrates.
“Nowhere else has an unbroken sequence of archaeological evidence stretching from hunter-gatherer times to full-blown farming,” he told BBC News Online.
The evidence for cultivated crops comes from seeds carefully sifted from the material excavated at Abu Hureyra. These had survived because they had been accidentally charred in domestic fires before eventually becoming buried.
Farming crisis: drought drove the hunter-gatherers into cultivation
Many years of ecological field work assessing present day vegetation was also necessary to provide a basis for interpreting the material found.
“What we expected to find from the hunter-gatherer levels at the site was lots of wild cereals. These are characteristically very skinny and we found plenty of them,” explains Professor Hillman.
“But then, at higher and later levels, we found things that did not belong there. There were these whacking, great fat seeds, characteristic of cultivation.”
The cultivated seeds found at Abu Hureyra are the oldest yet found.
Grindstone from about 9500-9000 BC
Excavated at Abu Hureyra, northern Syria.
A dry death
Professor Hillman and his team found that, as they looked through the archaeological record, the wild seed varieties gathered as food gradually vanished, before the cultivated varieties appeared. Those wild seeds most dependent on water were the first to die out, followed one by one by the more hardy ones.
This was a clue to why the hunter-gatherer people turned to cultivating some of the foods they had previously collected from the wild, and prompted Professor Hillman to look at independent climate records for the period.
What he found was evidence for a terrible drought: “It was very sharp and would certainly have been felt within a human lifetime, perhaps even in the space of 10 or so years.”
Geologist call this period the Younger Dryas, a 1000-year spell of cold and dry weather with interrupted the planet’s gradual warming from the last ice age.
The land had to be cleared before planting
Professor Hillman’s team suggest that as the wild grasses and seeds that the people relied on for food died out, they were forced to start cultivating the most easily-grown of them in order to survive.
Professor David Harris, also at UCL, said: “There came a point when this community had no option – they were stuck with agriculture.”
The archaeologists found no evidence that the irrigation was used to grow the first crops as the drought set it. Professor Hillman explains: “What they did was to take seed of the wild cereals from higher areas to the West, and sowed it close to Abu Hureyra in areas such as breaks in slope, where soil moisture was greatly enhanced naturally.”
“Wild stands of these cereals could not have continued to grow unaided in such locations because they would have been out-competed by dryland scrub. Therefore, these first cultivators had to clear the competing vegetation.”
Abu Hurerya, now under lake Assad, near the Turkish border in Syria.
These articles always ignore that the Koreans were farming rice about 15,000 years ago!
There does seem to be some dispute over the age of these grains, as the 12,700 BP date is so much older than the other grain domesticates and this doesn’t seem to have a sensible place in the chronology of the evolution of the Neolithic, it’s possible the dates are wrong (it happens) or that they were just an usually fat bunch of seeds. Also against this is that the Natufians generally show no other signs of agriculture at this era, and that the expanding Neolithic farmers who definitely were growing grain don’t show any cranial similarity to the Natufians. And there’s the issue that Abu Hurerya is debatable as a Natufian site….
Also against this being agriculture is that the grain in question, rye, really doesn’t feature in the Neolithic expansion as a founder crop. So, hmmm. Reserving judgement here.