Did Neanderthals eat their vegetables? Study provides first direct evidence of plants in Neanderthal diet

Homo neanderthalensis, adult male. Credit: John Gurche, artist / Chip Clark, photographer

The popular conception of the Neanderthal as a club-wielding carnivore is, well, rather primitive, according to a new study conducted at MIT. Instead, our prehistoric cousin may have had a more varied diet that, while heavy on meat, also included plant tissues, such as tubers and nuts.

Scientists from MIT and the University of La Laguna in Spain have identified human fecal remains from El Salt, a known site of Neanderthal occupation in southern Spain that dates back 50,000 years. The researchers analyzed each sample for metabolized versions of animal-derived cholesterol, as well as phytosterol, a cholesterol-like compound found in plants. While all samples contained signs of meat consumption, two samples showed traces of plants—the first direct evidence that Neanderthals may have enjoyed an omnivorous diet.

"We have passed through different phases in our interpretation of Neanderthals," says Ainara Sistiaga, a graduate student at the University of La Laguna who led the analysis as a visiting student at MIT. She and her colleagues have published their study in the journal PLoS ONE.

"It's important to understand all aspects of why humanity has come to dominate the planet the way it does," adds co-author Roger Summons, a professor of geobiology in MIT's Department of Earth, Atmospheric and Planetary Sciences. "A lot of that has to do with improved nutrition over time."

Unearthing a prehistoric meal

While scientists have attempted to reconstruct the Neanderthal diet, much of the evidence has been inconclusive. For example, researchers have analyzed bone fragments for carbon and nitrogen isotopes—signs that Neanderthals may have consumed certain prey, such as pigs versus cows. But such isotopic data only differentiate between protein sources—underestimating plant intake, and thereby depicting the Neanderthal as exclusively carnivorous.

Neanderthals had a taste for vegetables
The top panels show the coprolite, while the bottom panels show phosphate fluorescing under blue light. Credit: PLOS ONE, CC BY

Other researchers recently identified plant microfossils trapped in Neanderthal teeth—a finding that suggests the species may have led a more complex lifestyle, harvesting and cooking a variety of plants in addition to hunting prey. But Sistiaga says it is also possible that Neanderthals didn't eat plants directly, but consumed them through the stomach contents of their prey, leaving traces of plants in their teeth.

Equally likely, she says, is another scenario: "Sometimes in prehistoric societies, they used their teeth as tools, biting plants, among other things. We can't assume they were actually eating the plants based on finding microfossils in their teeth."

Oldest human poop provides dietary insights
A view of El Salt archeological site. Credit: Ainara Sistiaga
Signs in the soil

For a more direct approach, Sistiaga looked for fecal remains in El Salt, an excavation site in Alicante, Spain, where remnants of multiple Neanderthal occupations have been unearthed. Sistiaga and her colleagues dug out small samples of soil from different layers, and then worked with Summons to analyze the samples at MIT.

In the lab, Sistiaga ground the soil into a powder, then used multiple solvents to extract any organic matter from the sediment. Next, she looked for certain biomarkers in the organic residue that would signal whether the fecal remains were of human origin.

Specifically, Sistiaga looked for signs of coprostanol, a lipid formed when the gut metabolizes cholesterol. As humans are able to break down more cholesterol than any other mammal, Sistiaga looked for a certain peak level of coprostanol that would indicate the sample came from a human.

She and Summons then used the same geochemical techniques to determine the proportions of coprostanol—an animal-derived compound—to 5B-stigmastanol, a substance derived from the breakdown of phytosterol derived from plants.

Each sample contained mostly coprostanol—evidence of a largely meat-based diet. However, two samples also held biomarkers of plants, which Sistiaga says may indicate a rather significant plant intake. As she explains it, gram for gram, there is more cholesterol in meat than there is phytosterol in plants—so it would take a significant plant intake to produce even a small amount of metabolized phytosterol.

In other words, while Neanderthals had a mostly meat-based diet, they may have also consumed a fairly regular portion of plants, such as tubers, berries, and nuts.

"We believe Neanderthals probably ate what was available in different situations, seasons, and climates," Sistiaga says.

Sistiaga, Summons, and their colleagues plan to use similar geochemical biomarker techniques, coupled with micromorphological analysis, to analyze soil samples in Olduvai Gorge, Tanzania—a 1.8-million-year-old site where some of the earliest evidence of human ancestry have been discovered.

"We're working in a micro context," Sistiaga says. "Until now, people have carried out residue analysis on pots, tools, and other objects, but 90 percent of archaeology is sediment. We're opening a new window to the information that is enclosed in Paleolithic soil and sediment."

Explore further

Neanderthals may have made a meal of animal stomachs

More information: Sistiaga A, Mallol C, Galvan B, Summons RE (2014) The Neanderthal Meal: A New Perspective Using Faecal Biomarkers. PLOS ONE 9(6): e101045. doi:10.1371/journal.pone.0101045. dx.plos.org/10.1371/journal.pone.0101045
Journal information: PLoS ONE

Citation: Did Neanderthals eat their vegetables? Study provides first direct evidence of plants in Neanderthal diet (2014, June 25) retrieved 22 April 2019 from https://phys.org/news/2014-06-neanderthals-vegetables-evidence-neanderthal-diet.html
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Jun 25, 2014
When one notes the racially motivated violence that almost genetically identical homo sapiens perpetrate on each other then one shudders to think of the escalation in violence and inhumanity that surely would result had Neanderthal man, with his larger brain and more robust physique, survived to this day.

Jun 25, 2014
I have to imagine that old Uncle Neander ate whatever he could find that didn't eat him first.

No question in my mind that H. Sapiens both killed off, and sexual intercourse'd to death, the 4? other sentients (Neander, Denisovin , Erectus, and Flores) he shared the planet with.

Jun 25, 2014
http://www.ncbi.n...24693353 Nutrient-dependent/pheromone-controlled adaptive evolution: a model.

Cell type differentiation is nutrient-dependent in all individuals of all species and reproduction is controlled by the metabolism of nutrients to species-specific pheromones. If not, evolutionary theorists might still question whether or not ecological variation led to nutrient-dependent pheromone-controlled ecological adaptations in a modern human population that arose in what is now central China during the past ~30K years.

However, the results from this study also link the epigenetic landscape to the physical landscape of DNA in the organized genomes of species from microbes to man via conserved molecular mechanisms. That's how anyone familiar with biophysical constraints on mutation-initiated natural selection and the evolution of biodiversity will recognize that the modern human population is an example of ecological adaptations in Neandertals.

Jun 25, 2014
When the electric goes off and all the grocery stores are empty. Wonder what there gonna find in your stomach. Hunger says eat what you can. Good thing this study cleared it up for us.

Jun 25, 2014

We didn't kill them off, we simply evolved from them. Or rather, they evolved into us.

Jun 25, 2014
Two additional recent reports link substitution of the amino acid alanine for the amino acid valine (Grossman et al., 2013) to nutrient-dependent pheromone-controlled adaptive evolution. The alanine substitution for valine does not appear to be under any selection pressure in mice. The cause-and-effect relationship was established in mice by comparing the effects of the alanine, which is under selection pressure in humans, via its substitution for valine in mice (Kamberov et al., 2013).

These two reports (Grossman et al., 2013; Kamberov et al., 2013) tell a new short story of adaptive evolution. The story begins with what was probably a nutrient-dependent variant allele that arose in central China approximately 30,000 years ago. The effect of the allele is adaptive and it is manifested in the context of an effect on sweat, skin, hair, and teeth. In other mammals, like the mouse, the effect on sweat, skin, hair, and teeth is due to an epigenetic effect..." = ecoLOGICal adaptation.

Jun 26, 2014
I don't see why we have to report the anti-science pheromone troll to increase the signal-to-noise ratio. It would be simpler for science sites to filter out his handles and other telltale signatures.

@someone: All human subspecies had larger brains at the time. We live a simpler life, and don't need as much intellectual chops. (Cmp predators vs herbivores.)

As Seraut already noted, Neanderthals survived, and eminently so since their genes account for more alleles than the introgression warrants.

Jun 27, 2014
If getting food at the time of people before us was more difficult than it is today in a western country, why would they restrict themselves to only eating meat if vegetables were available?

With that being said, the ability to lose weight without having to always say no to the food you may crave the most seems to be advantageous. I shared some of my thoughts on this page where I also linked to a video that taught me about a weight loss phenomenon I did not know about: specialfatloss.com

I think that food is here to be eaten. Thus, I do not believe in having to completely stop eating delicious, healthy and lawful food to lose weight.If it can be done for the long term, what is the point? ​

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