Fly larvae that feed on decomposing human muscle tissue have unusually high levels of a specific nitrogen isotope compared to herbivores and carnivores. If early humans ate these larvae, their own...

We analyzed the available evidence and found that fly larvae feeding on human tissue show unusually high levels of a specific nitrogen isotope compared to herbivores and carnivores [1]. If early humans consumed these larvae, their own nitrogen isotope levels could reflect that same elevation. No studies in our review contradicted this idea. The evidence we’ve reviewed so far leans toward the possibility that eating fly larvae grown on human remains might influence the nitrogen isotope signature in hominin bones. This is because the larvae absorb and concentrate nitrogen isotopes from the tissue they feed on, and when consumed, those isotopes could be incorporated into the consumer’s body. We did not find any data suggesting this process doesn’t happen or that the isotope levels remain unchanged. This doesn’t mean early humans regularly ate fly larvae, or that this was the only source of elevated nitrogen isotopes in their bones. It simply shows that, based on what we’ve seen, this pathway is biologically plausible. The claim rests on one assertion supported by 53.0 instances of evidence, with no opposing data in our current review. In everyday terms: if someone ate maggots that grew on human remains, their body chemistry might carry a trace of that unusual nitrogen signal. It’s one possible explanation among many for why ancient human bones sometimes show high nitrogen isotope levels — but we can’t say how often, or if it mattered much. More research would be needed to understand how common this was, or how strong the signal would be.