Humankind made the transition from hunting to herding 10,000 years ago, according to a new study which looked into prehistoric urine.
It is thought to be the first time urine has been used to date an archaeological site.
The research is also believed to pinpoint the ‘crucial turning point in the history of humanity’ when the global population became animal herders.
It is currently not possible to tell apart the urine salts of humans to that of livestock but the researchers hope by refining the technique they will soon be able to.
Researchers say it is still a reliable gauge of society in the region around 8,000BC as it provides a look at population size and density.
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Study authors Jay Quade (left) and Jordan Abell (right) looking for urine samples at the site of an ancient Turkish settlement where salts left behind by animal and human urine give clues about the development of human society
The study, led by experts from Columbia University, tracked human population inthe region over 1,000 years.
A total of 113 samples of nitrate, sodium and chlorine were analysed from the site of Aşıklı Höyük in central Turkey which are commonly expelled in animal waste.
These samples revealed a boom in the numbers of humans, sheep and goats around 8,000 BC.
The study uses the abundance of urine salts over time to track the growth of the community in a world first.
‘This is the first time, to our knowledge, that people have picked up on salts in archaeological materials, and used them in a way to look at the development of animal management,’ says lead author Jordan Abell, a graduate student at Columbia’s Lamont-Doherty Earth Observatory.
‘And we thought, well, humans and animals pee, and when they pee, they release a bunch of salt,’ says Mr Abell.
‘At a dry place like this, we didn’t think salts would be washed away and redistributed.’
The oldest layers at the site that had any evidence of human habitation date back 10,400 years.
For 40 years only a slight increase in urine concentration was detected before a sudden spike lasting for 300 years, the researchers detected.
The timing is close to what the study authors expected to see but they say the sharp surge in population around 10,000 years ago may be evidence of a more rapid transition than previously thought.
Analysis from the team of archaeologist, published in the journal Science Advances.
Salts form this time period appeared in concentrations up to 1,000 times greater than the previous era indicating a boom in the umber of occupants – both animal and human.
They calculated that the density of people and animals around 10,000 years ago went from almost zero to approximately one person or animal for every 100 square feet (10 square metres).
View from the rooftops of reconstructed houses from the 8th and 9th century BC. A total of 113 samples were analysed from the site of Aşıklı Höyük in central Turkey and revealed a boom in the numbers of humans, sheep and goats around 8,000 BC
Students working on the western section of Aşıklı Höyük in central Turkey, where the evidence was found. The oldest layers at the site that had any evidence of human habitation date back 10,400 years. For 40 years only a slight increase in urine concentration was detected before a sudden spike lasting for 300 years, the researchers detected
Evidence from the site in turkey suggests that humans began domesticating sheep and goats around 8,450 BC. Not enough buildings at site from the time period to house all the people so some of the urine slats therefore came from animals
Evidence from the site suggests that humans began domesticating sheep and goats around 8,450 BC.
These practices evolved over the next 1,000 years, until the society became heavily dependent on the beasts for food and other materials.
An average of 1,790 people and animals lived – and urinated – on the settlement every day of the 100 year window assessed in the study.
They believe the urine salts belonged to a combination of humans and animals as the other evidence at the site indicates this many people would not have been able to fit in the buildings believed to be on the land.
This indicates that the urine salt concentrations can indeed reflect the relative amounts of domesticated animals over time.
Researchers hope to one day be bale to tell apart the urine salt samples of animals and humans and use the technique to study other areas where physical archaeological remains such as bones or buildings are non-existent.
Anthropologist and co-author Mary Stiner from the University of Arizona said the method could help clarify humanity’s relationship to animals during this period.
‘We might find similar trends in other archaeological sites of the period in the Middle East,’ she said.
‘But it is also possible that only a handful of long-lasting communities were forums for the evolving human-caprine relationships in any given region of the Middle East.’
