Neanderthals spent at least some time digesting plants, according to a new study that analyzed fossilized ancient feces to find the most direct evidence yet of a varied diet for man’s ancestors.
Carnivorous or exclusively meat diets have been the leading theory about what Neanderthals ate with some scientists suggesting the dominance of meat contributed to their extinction. While meat was their main source of food, they also ate plants, an analysis of fossilized fecal matter showed in a study released yesterday by PLoS One, a publication of the Public Library of Science.
The study found evidence of metabolized plant products in fossilized feces from a 50,000-year-old site in El Salt, Spain. It confirmed research from 2010 that found evidence of plant matter on the teeth of the ancient species and broadens the understanding of Neanderthal behaviour and early man, Ainara Sistiaga, the lead author said in a telephone interview.
Roger Summons, an astrobiologist at the Massachusetts Institute of Technology searching for organic matter that could be the hallmarks of life on Mars. He’s studied the earliest geological and biochemical cycles on Earth. But last year he received an unusual proposal from a student who wondered if she could use the sophisticated biochemistry equipment in his laboratory for a somewhat less sweeping scientific investigation, a detailed study of Neanderthal poop.
The researchers examined the fecal fossils for biologically derived indicators of the types of food the Neanderthals ate.
“We do all sorts of chemistry focused on microbes and this is our first foray into humans, so I think it’s exciting,” Summons said.
Understanding the diet of past human species is closely related to our own and it will help us gain perspective on our evolutionary constraints and adaptability.
Their findings indicate that Neanderthals predominantly consumed meat as suggested by high amounts of one such biomarker called coprostanol formed by the bacterial reduction of cholesterol in the gut. But they also found evidence for significant plant intake as shown by the presence of a compound called 5 beta-stigmastanol, found in plant sources. The rest of their diet is believed to have been made up from berries, nuts and root vegetables.
“It’s like any other fossil,” added MIT geobiology professor Roger Summons. “Fossils provide our most direct link with organisms from the past.”
The analysis opens a new way to study the biology of early humans, Sistiaga said. The samples at the Spanish site are the oldest fecal matter the method has been used on.
“It confirms what we were arguing about Neanderthal diets and it offers a whole new way of looking at Neanderthal diets,” Brooks, who wasn’t involved in the PLoS One study, said in a telephone interview.