The 1970s saw a new phase in the modern study of the impact of the Black Death — caused by the bacillus Yersinia pestis — in the history of medieval Central Eurasia. Scholars began to consider in greater detail the role of the Black Death in transformations in states, societies, economies, and cultures. Uli Schamiloglu has contributed to this debate. More recently, studies of the genetic history of Yersinia pestis have opened a new chapter in the study of this disease, which resulted in widespread mortality in the 14th and 15th centuries. The time and place for the origin of the plague in the time of Justinian and the Black Death have now been clarified, and Yersinia pestis has been identified from dental pulp. Laboratories in Germany and Canada are now rushing to identify further specimens of Yersinia pestis to document how it evolved from the mid-14th century on — possibly became more lethal — and how it established a long-term presence in the western part of Central Eurasia.