Fly larvae that feed on decaying human muscle tissue have unusually high levels of a nitrogen isotope called δ¹⁵N. If humans consume these larvae, their own δ¹⁵N levels may rise significantly, even...
Mechanism
Synthesis from 1 study
When meat rots, bacteria remove light nitrogen and leave behind heavy nitrogen, which fly larvae eat and store in their bodies. When people eat those larvae, they absorb that same heavy nitrogen, making their bodies show high levels—even without eating a lot of meat.
Most probable mechanism
When flesh starts to rot, bacteria break down proteins and let out a lot of light nitrogen gas, leaving behind more heavy nitrogen. Fly larvae eat this rotting flesh and the sticky liquid around it, soaking up the heavy nitrogen, which gets locked into their bodies as they grow. When humans eat these larvae, they take in that same heavy nitrogen, making their bodies show unusually high levels of it—even if they didn’t eat much meat.
Microbial decomposition of muscle tissue preferentially releases lighter nitrogen isotopes (14N) as volatile compounds such as ammonia and amines, leaving behind a residue enriched in heavier nitrogen isotopes (15N).
The remaining decomposing tissue and surrounding nutrient-rich fluid become progressively enriched in 15N due to continuous microbial nitrogen cycling and loss of 14N over time.
Fly larvae ingest this 15N-enriched substrate, incorporating the heavy nitrogen isotopes into their own proteins during growth and metabolic synthesis.
The accumulated 15N in larval tissues is retained and measured as elevated nitrogen isotope ratios, which persist through tissue processing and can be transferred to human consumers upon ingestion.
Evidence from Studies
Supporting (1)
Community contributions welcome
Neanderthals, hypercarnivores, and maggots: Insights from stable nitrogen isotopes
Contradicting (0)
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