Hunter-gatherer teams dwelling in southwest Asia might have began protecting and caring for animals practically 13,000 years in the past — roughly 2,000 years sooner than beforehand thought.
Historic plant samples extracted from present-day Syria present hints of charred dung, indicating that individuals have been burning animal droppings by the top of the Previous Stone Age, researchers report September 14 in PLOS One. The findings recommend people have been utilizing the dung as gas and will have began animal tending throughout and even earlier than the transition to agriculture. However what animals produced the dung and the precise nature of the animal-human relationship stay unclear.
“We all know immediately that dung gas is a invaluable useful resource, however it hasn’t actually been documented previous to the Neolithic,” says Alexia Smith, an archaeobotanist on the College of Connecticut in Storrs (SN: 8/5/03).
Smith and her colleagues reexamined 43 plant samples taken within the Nineteen Seventies from a residential dwelling at Abu Hureyra, an archaeological website now misplaced beneath the Tabqa Dam reservoir. The samples date from roughly 13,300 to 7,800 years in the past, spanning the transition from hunter-gatherer societies to farming and herding.
All through the samples, the researchers discovered various quantities of spherulites, tiny crystals that kind within the intestines of animals and are deposited in dung. There was a noticeable uptick between 12,800 and 12,300 years in the past, when darkened spherulites additionally appeared in a fireplace pit — proof they have been heated to between 500⁰ and 700⁰ Celsius, and doubtless burned.
The workforce then cross-referenced these findings towards beforehand revealed information from Abu Hureyra. It discovered that the dung burning coincided with a shift from round to linear buildings, a sign of a extra sedentary way of life, together with steadily rising numbers of untamed sheep on the website and a decline in gazelle and different small recreation. Mixed, the authors argue, these findings recommend people might have began tending animals outdoors their houses and have been burning the piles of dung at hand as a complement to wooden.
“The spherulite proof reported right here confirms that dung of some kind was used as gas,” says Naomi Miller, an archaeobotanist on the College of Pennsylvania who was not concerned with the examine.
Determining what animal left the dung may reveal whether or not animals have been tethered outdoors or not. Whereas the authors suggest wild sheep, which might have been extra accommodating to seize, Miller suggests the supply was in all probability roaming wild gazelle.
“Spherulites coming from off-site assortment of gazelle dung, saved till burned as gas, is to my thoughts a extra believable interpretation,” Miller says. Even when stored for a couple of days, she says, sheep wouldn’t produce giant quantities of dung.
“The entire thing is a basic whodunit,” says anthropologist Melinda Zeder, one thing maybe DNA evaluation may resolve (SN: 7/6/17). Gazelle is likely to be the supply, she says, and if captured younger, the animals might have even been tended for some time — even when they weren’t ultimately domesticated.
“The attention-grabbing factor is that individuals [were] experimenting with their setting,” says Zeder, of the Smithsonian Establishment in Washington, D.C. “Domestication is sort of incidental to that.”