Blame the gerbils

[Duncan Head]

http://www.bbc.co.uk/news/science-environment-31588671

http://www.pnas.org/content/early/2015/02/20/1412887112

Norwegian scientists taking the heat off rattus norvegicus.

[Swampster]

I thought that Asian marmots had already taken the heat off the rats.

I don't know if there is more in the paper, but it also doesn't seem to exclude that once yersina pestis had left the reservoir and reached higher population areas, the rats could still be a mode of transport for the fleas.

OTOH, there was a documentary a few years back where the thesis was that there weren't enough rats in many areas for them to be involved.

[Mark G]

I'm just waiting for Patrick to produce a source citing porus as the original cause.

[Erpingham]

I don't know if there is more in the paper, but it also doesn't seem to exclude that once yersina pestis had left the reservoir and reached higher population areas, the rats could still be a mode of transport for the fleas.

My understanding is that the gerbils, marmots and co act as a reservoir which sends waves of plague down this Spice Road.  As the marmots/gerbils don't travel with the caravans, there must be another host involved, unless the disease is passing directly between humans.  The ease of human-to-human transmission of the Black Death has always been a bit of mystery.

[Patrick Waterson]

The ease of human-to-human transmission of the Black Death has always been a bit of mystery.

Which is why some have speculated that it might have been pneumonic rather than bubonic plague.  For bubonic plague, the preferred vector has usually been Xenopsylla cheopis; this species does not survive well in temperate and cold climates, but, being holometabulous and nidiculous, it can persist where humans have created local areas of warmth in the 65-80 degrees Fahrenheit range, e.g. homes.

One of the accidents of history is that the Black Death did not occur a century or so earlier.  If it had, there may have been no Mongol Empire.

[Andreas Johansson]

One of the accidents of history is that the Black Death did not occur a century or so earlier.  If it had, there may have been no Mongol Empire.

It's been suggested that the Mongol empire helped cause the Black Death by improving communications and thus facilitating the spread of the epidemic.

(A fairly obvious objection is that by the 1340s the Mongol empire had seen its best days and if Pax Mongolica was the trigger the the epidemic ought have happened earlier.)