Ancient Europeans Left Little Evidence of Eating Insects
Dental-calculus DNA and chitinase-gene variation support limited insect consumption over about 9,000 years, but contamination and indirect inference rule out a genetic-destiny story.
The 60-second version
Ancient dental-calculus DNA and chitinase haplotypes are consistent with limited insect consumption in Europe over roughly 9,000 years.
Key points
- Researchers screened 1,028 libraries from 745 ancient Homo sapiens dental-calculus samples and found sparse insect DNA.
- Modern and ancient genomes showed latitude gradients near CHIA and CTBS associated with chitin digestion.
- Postmortem contamination and indirect genetic inference prevent conclusions about exact meals or an inherited aversion.
Verdict. The study supports uncommon ancient insect eating, not the claim that modern European dislike is simply encoded in genes.
Two evidence streamsDental calculus and chitinase genes told a similar story
A Science Advances study investigated whether insect eating was common in prehistoric Europe using two indirect genomic approaches. First, researchers screened 1,028 sequencing libraries from 745 Homo sapiens dental-calculus samples, mostly ancient Europeans, plus 18 Neanderthals and 96 great apes for comparison. Insect DNA reads were sparse in the anatomically modern human samples.
Second, they examined geographic variation near two stomach-expressed chitinase genes, CHIA and CTBS, using 2,396 modern genomes and 1,663 ancient genomes. Several haplotypes followed strong latitude gradients, and expression data associated common European variants with lower stomach chitin digestion. The gradients were already present around the rise of agriculture and persisted through later migrations.
What it supportsInsect consumption appears to have been uncommon
The two analyses converge on a cautious conclusion: intentional insect consumption was probably occasional in European Homo sapiens over roughly the past 9,000 years, and some detected traces may have been incidental. The comparison with primates helped calibrate the signal: groups known to eat more insects showed higher insect-DNA abundance, while ancient Europeans resembled chimpanzee populations with limited insect feeding.
This does not show that no European ever deliberately ate insects. Food practices vary across place, season, famine and social group, and the surviving samples are not a census. The genetic analysis also identifies population-level history; it cannot reconstruct an individual's meals or preferences.
The contamination problemInsect DNA in teeth is not automatically food
The authors explicitly found postmortem and environmental contamination. Some mummified or curated remains contained DNA from scavenging pests; one ancient Neanderthal sample even carried a species introduced to Europe only recently. Dental calculus can therefore admit environmental DNA after death, and insect DNA lacks some of the methylation patterns commonly used to authenticate ancient vertebrate DNA.
The researchers applied strict abundance, coverage and fragment-length filters, but they still warn that genuine insect reads do not necessarily prove eating. This is why low abundance supports a limited-consumption conclusion better than isolated positive hits support a specific ancient meal.
| Dental calculus | Records oral exposure but can include incidental intake and postmortem contamination. |
|---|---|
| Modern genomes | Reveal latitude-associated variants after accounting for population structure. |
| Ancient genomes | Show that the selected haplotype gradients predated or accompanied early agriculture. |
| Not measured | Taste, disgust, cultural rules or exact individual diets. |
Genes are not destinyThe paper does not find a genetic aversion to insects
The chitinase results concern the likely efficiency of digesting chitin, a component of insect exoskeletons. They do not identify a gene for disgust, prove that modern Europeans cannot digest insects, or show that culture is irrelevant. Food processing can reduce or remove chitin, and present-day choices arise from biology, availability, norms and experience together.
The study is peer-reviewed, open access and indexed by PubMed and PubMed Central; the authors declared no competing interests and released supporting data and code. Its strongest conclusion is historical and population-level: genomic evidence is consistent with limited insect consumption in ancient Europe. Claims that reluctance was simply 'written into the genes' go beyond the measurements.
The genomes may record adaptation to different food ecologies; they do not encode a simple, inevitable dislike of insects.