STOCKHOLM, SWEDEN—According to a Cosmos Magazine report, scientists have recovered DNA from pieces of birch bark chewed into sticky pitch by toolmaking hunters and fishers some 10,000 years ago. Archaeologists Per Persson and Mikael Manninen of the University of Oslo found the chewed bits of “gum” at a Mesolithic campsite on Sweden’s west coast, and asked Natalija Kashuba, then a researcher at Oslo’s Museum of Cultural History, to check them for genetic material. Although the style of artifacts at the site suggests the people who camped there came from the east, in what is now Russia, the DNA analysis indicates the two women and one man who chewed on these pieces of bark actually came from Europe, to the south. Persson explained that DNA obtained from such gums at other sites could offer information about migration patterns, relationships, diseases, and food preferences. To read about an engraved pendant dating to around the same period, go to “Mesolithic Markings.”