How “Ancient Chewing Gum” Highlights the Utility of DNA Analysis

Genomic DNA analysis has become a fundamental component of many high school teaching laboratories. Some of our best-selling kits involve simulations of practical, modern uses of the technique. Specifically, forensic DNA fingerprinting (for example, experiments 130 and 371) and simulations of human health screening and detection (like our best-selling COVID-19 and Sickle Cell Gene Detection experiments) are extremely popular across many scientific disciplines. These experiments are engaging for students due to their direct relevance to things they encounter in their daily lives.

A few years ago, scientists from the University of Copenhagen were able to analyze genomic DNA from a 5,700-year-old piece of birch tar to identify an incredible amount of information about the person chewing on it. The birch pitch may have been used in the construction or repair of ancient pottery, or even as rudimentary chewing gum. Either way, DNA was extracted from the sample and analyzed to understand more about the individual and the way they lived.

A chewed piece of birch pitch from southern Denmark. Figure 1A, “A 5700 year-old human genome and oral microbiome from chewed birch pitch”, Nature Comm. 10,

Amazingly, the DNA was well preserved and identified information about the individual and the things that they had recently eaten. For example, the scientists identified that the gum-chewer was a woman closely related to hunter-gatherers from mainland Europe, likely with dark skin, dark brown hair, and blue eyes. The gum also contained DNA from hazelnut and mallard, which might have been from a recent meal. It’s possible that additional analysis of this and other similar samples could tell scientists additional information. For example, analyzing bacterial DNA from samples could identify information about the oral microbiome of the individual.

There are many other practical applications for DNA analysis that you can explore in the classroom, including DNA profiling, DNA damage, and DNA barcoding. These fun topics are a perfect way to excite students and identify careers that incorporate the skills they are learning in the lab. To read the original academic article, published in Nature Communication, follow the link here.

Featured Image: Copyright Nicole Fara Silver, Flickr, https://www.flickr.com/photos/greatist/6002002397

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