The Evolutionary History of Yersinia pestis

In this chapter, we are surveying the main contours of the evolutionary development of Y. pestis since its divergence from Y. pseudotuberculosis, some six or seven millennia ago, until present. We focus particularly on (1) branching-off events leading to the emergence of new lineages, (2) the acquisition of new plasmids and genes necessary for the expansion of mammalian host range (3) the phylogeography of different branches and their strains, and (4) aDNA evidence on historical human pandemics. The chapter concludes by posing new questions for future research.