Extinct Pathogens Ushered The Fall of Ancient Civilizations, Scientists Say

Multiple Bronze Age civilization took a turn for the worse at the same time.

There was a societal crisis across the Ancient Near East and the Aegean due to the collapse of the Old Kingdom of Egypt.

Climate change and shifting loyalties have always been blamed. There is a new culprit in some bones.

The remains of two of history's most significant diseases were found in a cave in Crete, which was excavated by an archaeogeneticist.

The widespread illnesses caused by these pathogens can't be discounted as a contributing factor in the societal changes that took place around 2200 to 2000 BCE.

The necessity to re-introduce infectious diseases as an additional factor may have contributed to the transformation of early complex societies in the Aegean and beyond.

The bacterium that causes tens of millions of deaths is called yersinia pestis. The impact of Catastrophic prior to the Plague of Justinian has been difficult to measure.

Some of the lost history is being revealed thanks to recent technological and scientific advances.

The bacterium is thought to have been infecting people since the Neolithic period.

A Stone Age hunter-gatherer is thought to have died of plague thousands of years ago.

The evidence recovered from the cold regions had been the first to be found. The impact on ancient societies in warmer climates is not known.

Neumann and his team dug through bones recovered from a site on Crete that was cool and stable.

There were 32 people who died between 2279 and 1909 BCE. It was expected that the genetic data would show the presence of a few oralbacteria.

The presence of Y. pestis in two individuals is less expected than in two others.

There's a condition. It's more difficult to determine how the infections might have affected communities now that they're extinct.

One trait that made Y. pestis so infectious was that it couldn't be transmitted through fleas.

Humans get the bubonic version of the plague when they bite a flea. Pneumonic plague, which is transmitted via aerosols, could be caused by a different form of the bacterium.

The virulence and transmission routes of both pathogens are unknown because the S. enterica lineages lack key traits that contribute to severe disease in humans.

In regions of Crete with high population densities, both pathogens could have run amok.

It is unlikely that Y. pestis or S. enterica were the only culprits responsible for the societal changes observed in the Mediterranean at the end of the 3rd millennium BCE.

Plague and typhoid are diseases that don't leave traces on bones, so they're not often seen in the archaeological record. The team suggests that more detailed genetic screening of more remains from the Eastern Mediterranean could uncover the extent of the impact these diseases had on the people who lived there.

The research has appeared in a journal.