Agriculture is generally regarded as one of humanity’s greatest achievements, allowing people to develop societies where time could be spent on activities other than gathering enough food to survive. But when and where farming started, exactly, is a matter of debate among archaeologists. Typically, it’s thought to have originated around 12,000 years ago in the Middle East. But a new study led by archaeologists from Bar Ilan University in Israel argues that even earlier evidence exists. 

Their research, published in the journal PLOS ONE, centers around weed species found in an archaeological site in Israel that was once home to a camp of hunter-gatherers. Called Ohalo II, the camp was submerged and covered in lake sediment from the Sea of Galilee for 23,000 years. The plant matter discovered there is strikingly well preserved.

After studying 150,000 plant specimens, the scientists concluded that the residents of Ohalo II collected 140 plant species, including cereals like wild barley and wild oats, and grew them in trial plots—a small-scale, elementary cereal cultivation. They also found a grinding slab and evidence that the cereals were ground for meals, and sickle blades that might have been used to harvest them.

They also found 13 different types of "proto-weeds" among the edible plants. That's important because weeds thrive in cultivated fields and disturbed soils. A significant presence of weeds in archaeobotanical assemblages from Neolithic sites and settlements of later age is widely considered an indicator of systematic cultivation, according to the study. 

The evidence, the researchers say, adds up to “the earliest, small-scale attempt to cultivate wild cereals seen in the archaeological record.” 

People might not have been planting acres of wheat just yet, but they clearly knew their way around a field of barley.