The Resin That Remembered: How Ancient Birch Tar Is Rewriting the Story of Neolithic Life

The Taste of the Past

Thousands of years ago, someone—perhaps a young Neolithic woman or a farmer repairing a pot—chewed a lump of birch bark tar, softened it with saliva, and tossed it aside. What they could never have known is that, preserved in that lump of hardened resin, tiny traces of DNA and ancient proteins would survive for millennia.

Now, thanks to advances in biomolecular archaeology, that ancient gum is speaking again.

Making and using birch tar in Neolithic Europe. A possible chaîne opératoire [73] from the initial production of birch tar to the final use, including potential recycling of tar, and the biochemical analyses that can be used to investigate steps in this process. Credit: Proceedings of the Royal Society B: Biological Sciences (2025). DOI: 10.1098/rspb.2025.0092

In a sweeping study published in Proceedings of the Royal Society B,¹ researchers led by Anna White and Hannes Schroeder at the University of Copenhagen analyzed 30 samples of birch bark tar from Neolithic settlements across the Alpine region of Europe. Using a combination of chemical biomarker and ancient DNA analyses, they reconstructed a vivid picture of daily life: from the materials people handled to the foods they ate and even the bacteria that lived in their mouths.

“This kind of material acts like a molecular time capsule,” explains Dr. Sofia Lindgren, an archaeological geneticist at Uppsala University. “It traps traces of the human microbiome, diet, and environment in a single artifact. It’s archaeology at the molecular scale.”