Hunter-gatherer groups living in Southwest Asia may have started keeping and caring for animals nearly 13,000 years ago, roughly 2,000 years earlier than previously thought.
Ancient plant samples taken from present-day Syria show signs of charred manureindicating that people were burning animal droppings at the end of the Old Stone Age, researchers report September 14 in plus one. The findings suggest that humans were using the dung for fuel and may have started caring for animals during or even before the transition to agriculture. But which animals produced the dung and the exact nature of the animal-human relationship remain unclear.
“We know today that manure fuel is a valuable resourcebut it hasn’t really been documented before the Neolithic,” says Alexia Smith, an archaeobotanist at the University of Connecticut at Storrs (Serial number: 8/5/03).
Smith and his colleagues re-examined 43 plant samples taken in the 1970s from a residential dwelling at Abu Hureyra, a now-lost archaeological site under the reservoir of the Tabqa Dam. The samples date from approximately 13,300 to 7,800 years ago, spanning the transition from hunter-gatherer societies to agriculture and ranching.
Throughout the samples, the researchers found varying amounts of spherulites, tiny crystals that form in the intestines of animals and settle in the manure. There was a notable spike between 12,800 and 12,300 years ago, when dark spherulites also appeared in a fire pit, evidence that they were heated to between 500⁰ and 700⁰ Celsius, and probably burned up.
The team then compared these findings with previously published data from Abu Hureyra. He found that the dung burning coincided with a shift from circular to linear buildings, an indication of a more sedentary lifestyle, along with increasing numbers of wild sheep on the site and a decline in gazelle and other small animals. Combined, the authors argue, these findings suggest that humans may have begun to care for animals outside their homes and were burning available manure piles as a supplement to wood.
“The spherulite evidence reported here confirms that some type of dung was used as fuel,” says Naomi Miller, an archaeobotanist at the University of Pennsylvania who was not involved in the study.
Finding out which animal left the dung could reveal whether or not the animals were tied up outside. While the authors propose wild sheep, which would have been more accommodating to capture, Miller suggests the source was likely a roaming wild gazelle.
“Spherulites that come from off-site collection of gazelle dung, stored until burned for fuel, are, in my opinion, a more plausible interpretation,” says Miller. Even if kept for a few days, she says, the sheep would not produce large amounts of manure.
“It’s all a classic mystery,” says anthropologist Melinda Zeder, somewhat maybe DNA analysis could solve (Serial number: 7/6/17). Gazelle could be the source, she says, and if they were caught young, the animals may have been cared for for a while, even if they weren’t ultimately domesticated.
“The interesting thing is that people [were] experimenting with its environment,” says Zeder, of the Smithsonian Institution in Washington, DC “Domesticating is almost incidental to that.”