Archaeologists have used a novel method to trace the development of animal management at an ancient site in Turkey: urine deposits.
The research appears in the journal Science Advances.
Co-author Mary Stiner, an archeologist at the University of Arizona School of Anthropology, said the findings both broaden and deepen our understanding of ancient cultures.
"Originally, it was thought that the so-called Fertile Crescent was the sole heartland of the emergence of Neolithic, or, that is, farming and herding life ways. But now we realize it was over a broader area," she said.
Animal management ranks among humankind's most significant and impactful developments that led us toward modern civilization.
At the Aşıklı Höyük site in Turkey, remains of corrals, plants and dung show controlled use of sheep and goats 10,000 years ago.
The site, which lies on the Melendiz River in eastern Central Anatolia, possesses rich soils from marsh deposits.
At first, occupants would take home a lamb or kid from an adult sheep or goat they had killed, and then fatten it to eat over the harsh Anatolian winter.
Within 1,000 years, domesticated livestock outnumbered residents.
How and when that transition took place remained sketchy, until researchers hit upon the idea of using the quantity and pattern of urine salts to estimate animal activity at each layer of time.
"Susan Menser, one of our coauthors, was the first person to realize that there might be something funny going on there in regard to urine, because she saw high densities of nitratine crystals," said Stiner.
Nitratine, the sodium equivalent of saltpeter, forms only rarely in nature, according to Stiner. It's more typically associated with organic waste from animals.
Armed with this knowledge, the team mapped and dated more than 100 found samples.
They discovered a tenfold increase in urine salts over the mid to late 9th millennium BCE, but a 10-1,000 times increase over the first half millennium.
They were also able to trace when residents of Aşıklı Höyük moved animals to the periphery.
"By the end of the sequence, we began to see separation between residential areas and special use buildings," said Stiner. "There's plenty more to do with urine salts because of their high potential for looking at variation within a given archaeological layer. And we want to know a lot more about how humans and animals separated their activities within the community, and how that changed with time."
