Search for: All records

Yersinia pestis, the bacterium responsible for at least three pandemics in the past, is still a threat to modern populations. The bacterium has potential to evolve rapidly and persists in natural animal reservoirs around the globe. Epidemic diseases such as plague can dramatically alter and shape human demography, biology, and socio-cultural practices. Through the synthesis of biomolecular analyses with bioarchaeological data, researchers have begun to uncover the effects of past epidemics on modern populations and are also searching for the origins of the Y. pestis bacterium. Understanding the origins, behaviors, and consequences of diseases with epidemic potential in the past can contribute to ongoing discourse in public health, social policy, economy, and biology, as well as inspire positive changes in living populations. We review here recent literature on Y. pestis ecology and evidence of the bacteria’s evolution in prehistory before discussing ongoing research at the Hamin Neolithic settlement site that is suspected to have collapsed from an epidemic disease. 

Studies of the peopling of the Americas have focused on the timing and number of initial migrations. Less attention has been paid to the subsequent spread of people within the Americas. We sequenced 15 ancient human genomes spanning from Alaska to Patagonia; six are ≥10,000 years old (up to ~18× coverage). All are most closely related to Native Americans, including those from an Ancient Beringian individual and two morphologically distinct “Paleoamericans.” We found evidence of rapid dispersal and early diversification that included previously unknown groups as people moved south. This resulted in multiple independent, geographically uneven migrations, including one that provides clues of a Late Pleistocene Australasian genetic signal, as well as a later Mesoamerican-related expansion. These led to complex and dynamic population histories from North to South America.