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Re: Krakatoa and plague (was Re: The birds vs. the pterosaurs)

Tim Williams wrote:
> I have to ask, what is the connection between the eruption at Krakatoa and
> the spread of bubonic plague (caused by _Yersinia pestis_-carrying fleas)
> into Europe?  I'm genuinely very curious.

I'll send this to the list, but hopefully this will be the last post on
the subject (it's not all that relevant to dinos).

Bubonic plague is caused by a bacterium that lives naturally in the gut
of fleas. At temperatures above 25 degrees celcius the bacteria do not
effect the flea. However at lower temperatures, it causes clots to block
the flea's intestines. No matter how much blood the flea drinks, it is
always ravenously hungry since it can't digest anything. In desperation
it begins to attack any warm blooded prey that happen to be around.
Usually fleas are species specific - rat fleas will only generally feed
of rats, and even then on a specific species of rat.

With ash clouds covering most of the earth in 535-537 AD, temperatures
plunged well below average. Bubonic plague was native to a few lake
regions in Africa (Roman sources say the plague was brought from
Ethiopia by ivory traders). Usually the temperature is well above 25
degrees celcius, however with the cooling of the earth and a winter that
lasted two years the fleas began to suffer the effects of the bacteria
blocking their intestines. Thus in 542 the first occurance of bubonic
plague was recorded in Europe, seven years after the initial
"catastrophe" (as a PBS 2-hour series on the subject was called). In
Constantinople alone around 10,000 people were dying each day. Officials
stopped counting when the number reached half a million.



Dann Pigdon                   Australian Dinosaurs:
GIS Archaeologist           http://dannsdinosaurs.terrashare.com
Melbourne, Australia        http://www.alphalink.com.au/~dannj/