Beavers are spreading northwards into the Arctic and a new study provides detailed evidence of their expansion by dating the changes they have been making to the tundra landscape. The research, which combines tree ring analysis (looking at beaver browsing scars) with satellite imagery of surface water (highlighting dams), has allowed scientists to track and date beaver movements in remote areas of the Canadian Arctic.

At least seven individuals who lived about 100,000 years ago: the study—coordinated by researchers from the University of Bologna—is based on the analysis of ancient mitochondrial DNA from eight teeth found in the Stajnia Cave in Poland

New study shows that early humans living about 800,000 years ago depended on fire in smart, practical ways. Instead of searching for the “best” wood, they took advantage of what nature provided, mainly driftwood collected along the lakeshore. This reliable fuel supply helped them keep fires going for cooking and daily life, and may even explain why they kept coming back to the same spot. In other words, they weren’t just choosing a place to live, they were choosing a place where fire was easy to maintain.

Researchers identified the pathogen’s genetic material while examining a tooth from a naturally mummified skull housed at MUNARQ – the National Museum of Archaeology in La Paz. Using a method that reassembles previously unknown genomes from numerous short DNA fragments, they reconstructed a nearly complete, ancient genome of Streptococcus pyogenes.

The reconstructed genome shows clear similarities to modern strains of the globally widespread bacterium, which can cause a variety of illnesses ranging from harmless throat infections to scarlet fever and life-threatening toxic shock syndrome.

Despite the pathogen’s great medical significance: scarlet fever was historically one of the leading causes of death among children, little is known about its evolutionary history. This finding now shows that the bacterium was already circulating among indigenous populations in South America before European colonization: the young man from whom the tooth originated lived between 1283 and 1383 AD.

The study was made possible by a cooperation agreement between Eurac Research and the Bolivian Ministry of Cultures and has been published in Nature Communications.