Pee-oneering archeology. A new technique uses urine to study the ancient past
Salts from urine can trace where and when domestic animals moved into villages
A team of researchers excavating a 10,000 year old village in Turkey have developed a new technique that uses traces of ancient human and animal urine to understand occupation of the site.
The site, called Aşıklı Höyük, in Anatolia was inhabited just as humans in the area were transitioning from hunting animals to herding them — particularly sheep and goats — and keeping them inside their settlements in pens and corrals.
Analysis of bones and dung heaps has helped tell this story but left some important questions unanswered.
Jordan Abell, a geochemist and graduate student at Lamont Doherty Earth Observatory at Columbia University, and his colleagues were exploring new techniques to understand better how quickly this transition occurred and how many animals were kept in this small village.
Their solution was to see if traces of ancient urine could help tell the story.
They took more than 100 samples from various locations and depths at the site looking for trace salts from urine, including sodium, chlorine and nitrates.
To their delight they found the presence of pee helped fill in their story.
For the first several hundred years of the settlement, from about 10,400 to 10,000 years ago, the urine salt levels were on the order of ten times higher than they'd been before the settlement was established. They attribute this to human urine.
But from 10,000 years to about 9700 years ago they saw a huge jump in urine levels — to up to 1000 times the pre-settlement levels. They think this represents a quite rapid transition to keeping animals corralled within the village.
They were also able to estimate the density of animals and people within the village from the concentration of urine salts. They think about 1800 individuals might have occupied the village, which would have made the density of urinators about half of what it would be in a modern agricultural feed-lot.
The researchers hope they can develop their new technique. They want to find ways to distinguish between animal and human pee and perhaps use this new method of analysing ancient pee on other archeological sites where there are few other human and animal remains.