One of civilization’s most prolific killers shadowed humans for thousands of years without their knowledge.
The bacteria Yersinia pestis, which causes the plague, is thought to be responsible for up to 200 million deaths across human history — more than twice the casualties of World War II.
The Y. pestis death toll comes from three widespread disease outbreaks, known as epidemics: the sixth century Justinianic Plague that ravaged the Eastern Roman Empire; the 14th century Black Death that killed somewhere between 40% and 60% of the European population; and the ongoing Third Pandemic, which began in China in the mid-19th century and currently afflicts thousands worldwide.
Scientists long assumed that the deadly disease began infecting humans just before the earliest epidemic, the Justinianic Plague.
But recent paleogenetics research reveals that plague has been with us for millennia longer: Ancient DNA (aDNA) from the bacteria was recovered from human skeletons as old as 4,900 years. This means people were contracting and dying from plague at least 3,000 years before there’s any archaeological or historical evidence for an epidemic.
