Back to the ancient pandemics. On Monday, scientists revealed the oldest genome of pathogen ever sequenced. Revealing among other things that descendants of the germ that causes one of history's most dangerous plagues could give rise to a brand new pandemic today.
Led by geneticist from McMaster University. The team sequenced the DNA of bacteria extracted from the teeth of 2,150-year-old plague victims buried in the Bavarian cemetery. The victims died during the plague of Justinian. Which killed about half of Europe's population between the 5th and 8th centuries. This sometimes described as the last nail in the coffin of the Roman Empire.
Researchers were surprised by the genome of the Justinian germ was markedly different from that in the previously serious sequenced Black Death plague. Which killed two hundred million people in the 14th century.
The fact is, both outbreaks were caused by the same bacteria known as yersinia pestis. The strain that caused the Justinian plague seems to have gone extinct as the researchers report. But descendants of the Black Death strain are still around today. With thousands of infections reported every year.
So, the discovery in this sequences of plagues suggest that other, as yet unknown strains could have been what caused many in history's ancient pandemics. Like the Antonine plague that struck Rome 200s or even more devastating plague of Athens in the 5th century B.C.E.
It also means that another human infecting strain could be coming into being right now. The fact is, even though we've spent thousands of years with this particular germ. We know very little about the rate of genetic change in yersinia pestis. So, we don't know how quickly that could happen nor do we know exactly why the Justinian strained died out. Some biologists think it might have been eradicated by the cooling climate. Which proved inhospitable to the warm-loving bacterium cell.