The mysterious food in the diet of Neanderthals may be larvae

The study of rotting corpses of people hints that the mysterious chemical marker in the remains of Neanderthals may be from eating larvae.

The mysterious chemical signature that can be seen in the remains of Neanderthals could be explained if they often snacked on a special culinary garnish: larvae. This is according to a study published today in Science Advances.

The find adds to the picture that researchers draw about how our close relatives of ancient people provided themselves with food.

Scientists have long been puzzled by the fact that the bones of Neanderthals (Homo neanderthalensis) of the late Pleistocene (11,700-129,000 years ago) contain a nitrogen isotope at extreme levels usually observed in Megacarnivores, such as hyenas and wolves. The more meat an animal eats, the more nitrogen-15 it accumulates, and those at the top of the food chain have the most.

But "our intestines are not carnivorous intestines," says Bruce Hardy, an anthropologist at Kenyon College in Gambir, Ohio. "Our liver can only do so much to process protein." Thus, the levels of Neanderthals seemed incredibly high.

Melanie Beasley, an anthropologist from Purdue University in West Lafayette, Indiana, and her colleagues wondered if Neanderthals, instead of living a huge amount of meat, raised their level of 15N by cooking their food in some unique way. Beasley, the lead author of the study, was inspired by historical examples of indigenous groups consuming rotting food, as well as larvae - or fly larvae - that feer with it. Think about fermentation, she says. The rotting is similar: "The Westerner may say it's rotting, but in fact it's a method of storing food to break down meat," she adds.

To find out if Neanderthals could follow the same recipe, Beasley and her colleagues purchased muscle tissue samples from 34 donated human corpses who spent two years at the University of Tennessee, Knoxville Center for Forensic Anthropology. They found that the levels of 15N in the flesh increased as it decomposed - and when they sampled hundreds of larvae in the tissue, they measured up to 43 parts per thousand isotopes in the larvae compared to up to 8 parts per thousand in the tissue.

Enjoy your meal

Both results suggest that if Neanderthals enjoyed rotten meat and larvae, it could be a more viable explanation for their mysteriously high levels of 15N than eating an incredibly large amount of meat. And it's probably more comprehensive food than just protein, Beasley says. "When you get lean meat and fatty larvae, you have a more complete nutrient that you consume."

Amanda Henry, a bioarchaeologist from Leiden University in the Netherlands, says that the study expands our view of the food chain beyond the Western perspective. But, according to her, the results will weigh more if the Researchers also studied the larvae and meat of animals that Neanderthals would actually consume, such as deer.

Even then, it will be difficult to say for sure whether our ancient relatives had fly larvae, says Hardy. Without an isotope or other marker specific to the consumption of the larva, "it will be very difficult to demonstrate that this is what is happening," he says.

Herve Bocherens, a biogeologist from the University of Tübingen in Germany, says that the conditions of the study probably do not accurately imitate the habitat of ancient Neanderthals. Neanderthals probably stored meat in various remote warehouses, which he said would have preserved it to some extent, which means that it would have decomposed differently than bodies in a forensic laboratory. He also believes that there may be other larva-free explanations for the level of 15N Neanderthals: perhaps they have supplemented their protein-rich diets with starchy plant products, for example.

To better simulate an equivalent situation, Beasley hopes to cooperate with indigenous groups that still practice meat rotting methods and test the products they prepare. "We recognize the preliminary nature of these conclusions and encourage further investigation," she and her colleagues write in their article.