Ancient birch bark 'chewing gum' has preserved human DNA for over 5,000 years.

In 2019, researchers from the University of Copenhagen published a groundbreaking study in the journal Nature Communications. They successfully sequenced a complete ancient human genome from a piece of birch bark pitch found at the Syltholm site on Lolland, an island in Denmark. The sample dates back approximately 5,700 years to the Neolithic period.Birch bark pitch is created by heating birch bark and was commonly used as an adhesive for tool-making. Because it contains antiseptic properties, scientists believe ancient humans also chewed it to treat oral infections or simply as a gum. The hydrophobic nature of the tar protects organic material from water and oxygen, which prevents the degradation of DNA over millennia.The DNA belonged to a female individual the researchers named 'Lola.' The genetic analysis revealed she had dark skin, dark hair, and blue eyes, a combination common among European hunter-gatherers at the time. Beyond human DNA, the sample contained traces of hazelnuts and mallard duck, providing direct evidence of her last meal.The study also identified oral microbes and pathogens, including the Epstein-Barr virus and bacteria that cause gum disease and pneumonia. This discovery is significant because it marks the first time an entire ancient human genome was extracted from something other than human bone or teeth. It proves that 'chewing gum' can serve as a vital source of genetic information for understanding human evolution and prehistoric health.