Birch Tar Made via Neanderthal Techniques Inhibits S. aureus, Pointing to Dual Tool-and-Medicine Role

The PLOS One study tested birch tar produced by underground dry distillation and by condensation on stone surfaces, both techniques inferred from European Middle Paleolithic residues. All batches inhibited S. aureus at concentrations recoverable from archaeological finds, confirming antibacterial activity independent of production method. The work directly addresses whether the tar’s known adhesive properties could have been recognized for medicinal use during the Pleistocene.

Broader evidence of Neanderthal plant processing, including the 2012 El Sidrón dental calculus study showing poplar and willow compounds, suggests repeated experimentation with bioactive materials. Ethnographic records from Siberian and North American groups document birch tar applied to skin infections, supplying an analog that the authors used to frame their results. This dual-function interpretation challenges the long-standing assumption that Neanderthal material culture was narrowly technological.

Mainstream coverage has underplayed cognitive implications: recognizing and deliberately applying an antibacterial adhesive implies both observational learning and transmission of a multi-step process. The study’s limitation is its reliance on modern S. aureus strains rather than ancient microbiomes; ancient-DNA sequencing of wound-associated residues from Neanderthal fossils would strengthen the case.

Future work should target sealed sediment contexts at sites such as Königsaue or Campitello to test whether tar residues co-occur with human skeletal lesions showing healing, providing a direct archaeological test within the next five years.