Well, this is interesting:
Black rats may not have been to blame for numerous outbreaks of the bubonic plague across Europe, a study suggests.
Scientists believe repeat epidemics of the Black Death, which arrived in Europe in the mid-14th Century, instead trace back to gerbils from Asia.
The Black Death, which originated in Asia, arrived in Europe in 1347 and caused one of the deadliest outbreaks in human history.
Over the next 400 years, epidemics broke out again and again, killing millions of people.
It had been thought that black rats were responsible for allowing the plague to establish in Europe, with new outbreaks occurring when fleas jumped from infected rodents to humans.
Instead, the team believes that specific weather conditions in Asia may have caused another plague-carrying rodent – the giant gerbil – to thrive.
And this then later led to epidemics in Europe.
“We show that wherever there were good conditions for gerbils and fleas in central Asia, some years later the bacteria shows up in harbour cities in Europe and then spreads across the continent,” Prof Stenseth said.
He said that a wet spring followed by a warm summer would cause gerbil numbers to boom.
Notice this doesn’t say that rats had nothing to do with the outbreaks, just that they originated with gerbils. What’s nice about this hypothesis is that it includes a testable claim:
The team now plans to analyse plague bacteria DNA taken from ancient skeletons across Europe.
If the genetic material shows a large amount of variation, it would suggest the team’s theory is correct.