Using chemical clues from Neanderthal bones, researchers have placed the species at the top of the food chain, alongside apex predators like lions – feasting on big animals such as mammoths or bison. However, experts have been missing out on one of their key, fat-rich, and easily collectible food sources: Maggots.
So how did Purdue University anthropologist Melanie Beasley and her colleague conclude that Neanderthals actively consumed fly larvae?
The elements found in the bones of animals could provide various insights, including what they devoured when alive. Stable nitrogen has two isotopes, Nitrogen-14 (lighter and abundant) and Nitrogen-15 (heavier and less common), which act like dietary fingerprints. Nitrogen-15 builds up step by step in the food chains: plants have very low levels, herbivores gather up some from plants, and meanwhile, the carnivores have the highest.
The analysis of nitrogen isotopes from Neanderthal bones from across Europe consistently showed high Nitrogen-15 values, as high as or higher than wolves or hyenas, suggesting a diet heavy on meat. But this pattern puzzled researchers. Unlike other apex predators, humans, including our extinct cousins, can’t handle high levels of proteins. If they ate as much protein as hypercarnivores, they might end up with a condition historically known as “rabbit starvation,” i.e., protein poisoning.
The team suspected that something else about Neanderthal’s diet was inflating Neanderthal’s nitrogen-15 values. Interestingly, prehistoric Homo sapiens, too, had a similar nitrogen signature as Neanderthals.
Since some Indigenous tribes from the Arctic and subarctic are known to eat maggots from putrefied meat, the researchers considered maggots a potential factor driving those isotope spikes. Surprisingly, Melanie found that the maggots feeding on decomposing meat have the highest nitrogen-15, almost four times higher than a lion.
To test if maggots could spike those isotope levels, the researchers analyzed fly larvae feeding on decomposing human muscle tissue. They found that as flesh breaks down, lighter nitrogen atoms escape as gases, leaving heavier ones behind. Maggots feasting on this rotting tissue become enriched in heavy Nitrogen. Winter-collected larvae showed even higher values, perhaps from slower decay in the cold. Eating maggots alongside tainted meat could explain their elevated isotopes without needing a hypercarnivore diet.
"In the particular case considered here of Eurasian Late Pleistocene hominins," the research team conclude in the new study, "we suspect that the high [Nitrogen-15] values reflect routine consumption of stored decomposing fatty animal substrates laced with highly-enriched maggots."
The study has been published in Science Advances.
Source: Purdue University
