Found: Oldest Known Poop From a Human Ancestor
Archaeologists in Spain have dug up the oldest known feces from a human ancestor. Their find is detailed in PLoS ONE.
Retrieved from El Salt, an open-air site near Alicante, Spain, the samples date back around 50,000 years, firmly trouncing the previous record of 14,000 years.
Dr. Ainara Sistiaga and her team were able to identify the buried fecal matter by the predominance of coprostanol, a compund considered to be a clear biomarker of human excrement.
"5β-stanols, including coprostanol and 5β-stigmastanol, can be used as fecal biomarkers because they are uniquely formed in the intestinal tract of most higher mammals during metabolic reduction of cholesterol and phytosterols," Sistiaga told RCScience.
Besides advancing the quest to extend fart jokes further back into the Paleolithic, the find is important for a simple reason: if you want to know what went in, you have to examine what came out. Fossilized feces are the best clues we have for learning what our ancestors ate. The current discovery presents the first direct evidence that Neanderthals consumed an omnivorous diet of meat and vegetables.
Organic molecules called sterols permitted the researchers to glean that nugget of information. Divided into phytosterols (from plants) and zoosterols (from animals), they're hearty molecules that give cell membranes their structure. When we eat plants or animals, traces of these sterols will make it through digestion to be excreted in feces. The type of sterols in our poop gives away what we've been eating. In the case of the Neanderthal feces at El Salt, the researchers found evidence of a meat-dominated diet occasionally augmented by vegetables, probably some sort of tuber. Lot's of meat and a few potatoes.
"Our results also have implications regarding digestive systems and gut microbiota evolution," the researchers say.
They found evidence that cholesterol was converted to coprostanol, a process known to be carried out by gut bacteria. It would appear that Neanderthals had their own army of gut flora 50,000 years ago.
Source: Sistiaga A, Mallol C, Galva ́n B, Summons RE (2014) The Neanderthal Meal: A New Perspective Using Faecal Biomarkers. PLOS ONE 9(6): e101045. doi:10. 1371/journal.pone.0101045