The commonly held belief that humans domesticated plants before animals. And that is called into question by clues found in ancient animal feces in a recently published paper in PLoS One

Dung is frequently used by humans as fuel and might have come from animals cared for by humans throughout or even before the agricultural revolution. At the minimum, this demonstrates that at the end of the Old Stone Age, people were burning animal droppings. However, it is still unknown which animals created the feces and what the precise animal-human interaction was.

One of the longest documented sequences of humanity's transition from hunter-gatherers to farmers was discovered during excavations in Abu Hureyra, the site that yielded the dung, in what is now Syria in the early 1970s. With easy access to floodplains, steppe, and woods, this region of the Fertile Crescent was particularly ideal for pre-historic people. It was home to a wide variety of flora and wildlife, and it was first inhabited by humans in the Stone Age during the Epipalaeolithic period, when there were only about 200 individuals.

Due to ongoing hostilities, this location is now buried beneath Lake Assad in a difficult-to-access area. Fortunately, a ton of samples from the site have been properly conserved and cataloged by previous archaeologists. The scientists later compared these results to previously released data from Abu Hureyra.

First author, Alexia Smith, an archaeobotanist at the University of Connecticut,

“We know today that dung fuel is a valuable resource, but it hasn’t really been documented prior to the Neolithic.”

43 plant samples that were originally collected in the 1970s from a house at Abu Hureyra, an ancient location that is now submerged beneath the Tabqa Dam reservoir, were reexamined by Smith and her colleagues. The samples span the transition from hunter-gatherer communities to farming and herding, dating from around 13,300 to 7,800 years ago.

Spherulites, microscopic crystals that develop in animal intestines and are excreted in dung, were present in variable concentrations in all of the samples, according to the researchers. When blackened spherulites also formed in a fire pit, showing that they were heated to between 5000 and 7000 Celsius, and likely burned, there was a substantial increase between 12,800 and 12,300 years ago. The authors state

"We were surprised when we realized that hunter-gatherers were bringing live animals to Abu Hureyra… and keeping them outside of their hut. This is almost 2,000 years earlier than what we have seen elsewhere, although it is in line with what we might expect for the Euphrates Valley."

Smith and her colleagues created a timeline using the surviving evidence of the many and repetitive dung-related actions. Some actions, such as using the waste as fuel or the manure to line the flooring of homes, left sharper, more recognizable use signals.

They discovered that the early Epipalaeolithic period (13,300–12,800 calBP) had few clusters and low isolated spherulites, indicating that there was little interaction between the hunter-gatherers and live animals. However, there was a spike of dung associated with firepits and another lot of spherulite clusters near a work area right outside the settlers' homes during the second part of the Epipalaeolithic period (12,800-12,300 calBP), which is consistent with a dramatic shift in architecture to more durable homes.

It was discovered that the dung burning occurred at the same time as a change in building style from circular to linear, a sign of a more sedentary lifestyle, as well as a steady increase in the number of wild sheep at the location and a decrease in gazelle and other small wildlife. Spherulites in large quantities and extra manure being burned indicate that only a few animals were kept and cared after on the property. Researchers believe that a practical approach to get rid of extra manure was to use it as fuel to enhance wood fires. The scientists claim that when taken together, these findings indicate that humans may have started taking care of animals outside of their homes and used the nearby piles of dung as a substitute for wood.

Identifying the animal that left the feces may help determine whether or not the animals were tethered outside. Even though the writers suggest wild sheep, which would have been easier to catch, gathering dung from roving wild gazelle is also likely. The researchers also speculate that the animals may have been used to store live meat to account for variations in the presence of the principal prey of these hunter-gatherers. Additionally, it would have allowed the hunter-gatherers to live there all year round.

Prior to this; first domesticated grains occured 11,500 years ago (calBP), which was followed by a number of other crops. Animal domestication was not clearly demonstrated until roughly 10,000 years ago, during the Pre-Pottery Neolithic B culture.