HEALTH × GENETICS
The Black Death
1346 CE
History · Middle Ages · Holocene · Meghalayan
The Black Death, which reached the Mediterranean in 1346 and killed perhaps half of Europe's people by 1353, has been traced by ancient DNA to a source near Lake Issyk-Kul, in present-day Kyrgyzstan.
The Black Death, which reached the Mediterranean in 1346 and removed perhaps half the European population by 1353, has had its source identified by ancient DNA. Victims buried beside Lake Issyk-Kul, in present-day Kyrgyzstan, under headstones dated 1338 and 1339 mentioning a pestilence, carried a strain of Yersinia pestis ancestral to the lineages of the pandemic and closely related to bacteria persisting in the marmot colonies of the region. The term ancestral has a precise sense: on the family tree of the strains, the lineages associated with the pandemic diverge from a single node, and this one occupies that node and not one of the branches issuing from it. The germ entered Europe once from that source, a later wave returning eastward and giving rise to the modern epidemics.
Why it matters
The origin of a pandemic that had remained undetermined for seven centuries is thus reduced to a decade, a region and an identified animal reservoir. The result sets aside the explanation by urban sanitary conditions: the agent comes from a wild mountain reservoir, still active. Systems for monitoring animal reservoirs proceed directly from this kind of finding.
Dating & uncertainty
The arrival of the pandemic in the Mediterranean in 1346 and 1347 is documented by written sources. The contribution of genetics bears on what precedes: the Issyk-Kul cemeteries, whose headstones of 1338 and 1339 mention pestilence, yielded a strain occupying the ancestral node of the diversification associated with the pandemic, whose closest wild relatives live among the marmots of the Tian Shan.
Our species’ history as one day
23:56:533 min 7 s before midnight
if the 315,000 years of Homo sapiens were compressed into a single day