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Black death was not spread by rat fleas- say researchers

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AardvarkGoodSwimmer
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01 May 2014, 5:30 pm

S h i t .

Okay, it's not good.

And one good response is to play the cards of famous people on the Autism Spectrum. To lay those cards on the table:
Thomas Jefferson,
Jane Austen,
Nikola Tesla.

And then famous people from our own time:
Daryl Hannah,
Dan Aykroyd,
Susan Boyle.

And then make the point, a person shouldn't have to be famous to be treated with courtesy and respect.



The_Walrus
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02 May 2014, 6:20 am

AardvarkGoodSwimmer wrote:
I'm reading the article saying in the 25 skeletons or at least some of them, it was the plague.

Quote:
http://www.theguardian.com/science/2014 ... don-plague

" . . . By extracting the DNA of the disease bacterium, Yersinia pestis, from the largest teeth in some of the skulls retrieved from the square, the scientists were able to compare the strain of bubonic plague preserved there with that which was recently responsible for killing 60 people in Madagascar. To their surprise, the 14th-century strain, the cause of the most lethal catastrophe in recorded history, was no more virulent than today's disease. The DNA codes were an almost perfect match. . . "

There are two serious problems with this study. Firstly, it presumes that Y. pestis was the cause of Black Death, which is almost certainly not true. Of course Y. pestis DNA is going to be similar to Y. pestis DNA! They should not have started with that assumption, as it causes circular reasoning.

Secondly, they found Y. pestis DNA in a lot of the teeth. This is the same issue that unstuck some French researchers in 1998, who found that 20 out of 23 "plague victims" had Y pestis DNA in their teeth. Gilbert et al. tried to recreate their results in 2004, failed, and suggested that a success rate like that after 600 years is probably due to contamination.

I find it strange that the discovery that people were infected with a flea-vectored disease causes people to presume that it couldn't have been flea-vectored.



Janissy
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02 May 2014, 7:40 am

The_Walrus wrote:
AardvarkGoodSwimmer wrote:
I'm reading the article saying in the 25 skeletons or at least some of them, it was the plague.

Quote:
http://www.theguardian.com/science/2014 ... don-plague

" . . . By extracting the DNA of the disease bacterium, Yersinia pestis, from the largest teeth in some of the skulls retrieved from the square, the scientists were able to compare the strain of bubonic plague preserved there with that which was recently responsible for killing 60 people in Madagascar. To their surprise, the 14th-century strain, the cause of the most lethal catastrophe in recorded history, was no more virulent than today's disease. The DNA codes were an almost perfect match. . . "

There are two serious problems with this study. Firstly, it presumes that Y. pestis was the cause of Black Death, which is almost certainly not true. Of course Y. pestis DNA is going to be similar to Y. pestis DNA! They should not have started with that assumption, as it causes circular reasoning.

Secondly, they found Y. pestis DNA in a lot of the teeth. This is the same issue that unstuck some French researchers in 1998, who found that 20 out of 23 "plague victims" had Y pestis DNA in their teeth. Gilbert et al. tried to recreate their results in 2004, failed, and suggested that a success rate like that after 600 years is probably due to contamination.

I find it strange that the discovery that people were infected with a flea-vectored disease causes people to presume that it couldn't have been flea-vectored.


I do agree that starting with an assumption (such as 'it was caused by Y. pestis) leads to confirmation bias. There are researchers who think one of the viral hemorrhagic fevers is more likely. But I don't think Y. pestis can be ruled out either. I think it should be treated as an open question: "What caused the Black Death" without assumptions.



eric76
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02 May 2014, 9:10 pm

The_Walrus wrote:
I find it strange that the discovery that people were infected with a flea-vectored disease causes people to presume that it couldn't have been flea-vectored.


I read years ago that most deaths in the black plague were pneumonic plague rather than bubonic plague. So the recent "news" seemed more like what was already known just becoming better known.

By the way, there is also septicemic plague, again from the same infectious agent, but the infection is in the blood instead of the lungs or the lymph nodes.