A team of European researchers studied prehistoric chewed pitch (chewing gum made from tree resin or pitch) found 30 years ago in Huseby Klev, a site near Gothenburg city in Sweden, alongside human remains. The ancient chewing gum has genetic material not only from humans, but also from birds, mammals, and numerous pathogens. The three pieces of pitch have tooth imprints of the individuals who chewed them and are about 9,890 years old. That makes this the oldest chewing gum ever known. The researchers conducted a detailed DNA analysis of the chewed pitch and recently published their findings, …