Scientists have discovered the first molecular evidence that Neanderthals not only ate a range of cooked plant foods, but also understood its nutritional and medicinal qualities.
Until recently Neanderthals were thought to be predominantly meat-eaters. However, evidence of dietary breadth is growing as more sophisticated analyses are undertaken.
The team combined pyrolysis gas-chromatography-mass spectrometry with morphological analysis of plant microfossils to identify material trapped in dental calculus (calcified dental plaque) from five Neanderthals from the north Spanish site of El Sidrón.
The results, published in the journal Naturwissenschaften, provide another twist to the story – the first molecular evidence for medicinal plants being used by a Neanderthal individual.
The researchers said the starch granules and carbohydrate markers in the samples, plus evidence for plant compounds such as azulenes and coumarins, as well as possible evidence for nuts, grasses and even green vegetables, argue for a broader use of ingested plants than is often suggested by stable isotope analysis.
“The varied use of plants we identified suggests that the Neanderthal occupants of El Sidrón had a sophisticated knowledge of their natural surroundings which included the ability to select and use certain plants for their nutritional value and for self-medication. While meat was clearly important, our research points to an even more complex diet than has previously been supposed,” said lead author Prof Karen Hardy of the Universitat Autònoma de Barcelona and the University of York, UK.
Earlier study by the team had shown that the Neanderthals from El Sidrón had the bitter taste perception gene. Now trapped within dental calculus researchers found molecular evidence that one individual had eaten bitter tasting plants.
“The evidence indicating this individual was eating bitter-tasting plants such as yarrow and chamomile with little nutritional value is surprising. We know that Neanderthals would find these plants bitter, so it is likely these plants must have been selected for reasons other than taste,” said Dr Stephen Buckley of the University of York.
Prof Matthew Collins, who heads the BioArCh research facility at York, said: “Using mass spectrometry, we were able to identify the building blocks of carbohydrates in the calculus of two adults, one individual in particular having apparently eaten several different carbohydrate-rich foods. Combined with the microscopic analysis it also demonstrates how dental calculus can provide a rich source of information.”
The researchers say evidence for cooked carbohydrates is confirmed by both the cracked/roasted starch granules observed microscopically and the molecular evidence for cooking and exposure to wood smoke or smoked food in the form of a range of chemical markers including methyl esters, phenols, and polynuclear aromatic hydrocarbons found in dental calculus.
“Our research confirms the varied and selective use of plants by Neanderthals,” added co-author Prof Les Copeland of the University of Sydney, Australia.
The study also provides evidence that the starch granules reported from El Sidrón represent the oldest granules ever to be confirmed using a biochemical test, while ancient bacteria found embedded in the calculus offers the potential for future studies in oral health.
Bibliographic information: Hardy et al. 2012. Neanderthal medics? Evidence for food, cooking, and medicinal plants entrapped in dental calculus. Naturwissenschaften, published online 18 July 2012; doi: 10.1007/s00114-012-0942-0