Emergence and spread of ancestral Yersinia pestis in Late-Neolithic and Bronze-Age Eurasia, ca . 5,000 to 2,500 y B.P.

Abstract

Evolutionary history of any living organism is as fascinating as it is complex. The causative agent of plague, the bacterium Yersinia pestis, is no exception. Having diverged from the enteropathogen Yersinia pseudotuberculosis, ancestral strains of Y. pestis spread all over Late-Neolithic Eurasia. In their study, Andrades Valtue ña et al. (1) present a tour de force by reporting 17 new prehistoric Y. pestis genomes from Eurasian human burials (adding to 13 previously published) (1-7). Furthermore, their work, together with previously published data, lays the foundations for a new classification of Y. pestis strains and broadens our insight into the dynamics of emergence and spread of Y. pestis in prehistoric Eurasia.Of the ancient genomes, the authors classify the two oldest (previously published) genomes as the "preLNBA-" (pre-Late Neolithic/Early Bronze Age) lineage and 26 others as the "LNBA-" lineage (1). PreLNBA-genomes are from Latvia and Sweden, dated, respectively, to 5,300 to 5,050 and 5,040 to 4,867 y B.P. The low number of reported pre-LNBA-genomes suggests that these lineages may have died out several centuries after their rise. In contrast to preLNBA-lineages, LNBA-lineages were present over a wide geographic area (from Lake Baikal to central Europe) and existed for at least 2,500 y-from ca. 5,100 y B.P. until 2,736 to 2,457 y B.P. (the date of the latest genome).The data reported by Andrades Valtue ña et al.(1) indicate that the LNBA-lineage had a different evolutionary story compared to later lineages, such as "Branch 1" causing the second and third plague pandemics, characterized by phylogenetic and global focal diversity (8-10

Neolithic humans and dogs - transient reservoirs for Yersinia pestis

“…Some of these species could have been natural reservoirs and vectors of Y. pestis 1 , but if so, how could they have transmitted the bacterium to humans? An infection would have been feasible through close contact with a Y. pestis-positive animal 22 . However, this scenario would likely lead to single zoonotic events that might have caused limited outbreaks, and it does not explain the wide geographical distribution of the LN strains.…”