TL;DR: earliest evidence of ancestor to Yersinia pestis found in Kyrgyztan. Not saying that's the origin, just the earliest known find of an ancestor so far.
Condensed version:
"People who died in a fourteenth-century outbreak in what is now Kyrgyzstan were killed by strains of the plague-causing bacterium Yersinia pestis that gave rise to the pathogens responsible several years later for the Black Death, shows a study of ancient genomes."
"Other evidence puts the origins of the Black Death in this part of Central Asia. Among modern strains of Y. pestis bacteria, those sampled from marmots and other rodents in Kyrgyzstan, Kazakhstan and Xinjiang in northwest China, surrounding the Tian Shan mountain range, were most closely related to the Kara-Djigach strain. 'We can’t really say it’s that village or that valley, but it’s likely that region,' says Krause."
"[Miscellaneous scholar] is less sure of the study’s conclusion that the plague’s ‘big bang’ occurred around the time of the Kyrgyzstan deaths in 1338–39. Green has hypothesized, on the basis of genetic evidence, that the thirteenth-century expansion of the Mongol Empire catalysed the spread and diversification of Y. pestis strains responsible for the later Black Death."
> held an unusually high number of tombstones dated to 1338 and 1339, ten of which made explicit reference to a pestilence.
> “When you have one or two years with excess mortality, it means something funny is going on there,” Slavin said at a press briefing.
When you have more than a couple of years of 'excess mortality' the ratio of tombstones to deaths may also decline. That's why we also look for mass graves. They can contain people nobody wants to bury (eg, dead Vikings after a failed invasion) or people nobody can bury.
An unusually high number in 1338 and 1339 may indicate a two year plague, or that people gave up it 1340.
The linked article is about an immediate ancestor to the specific strain that caused the black plague. Your article is about a much more distinctly related strain and not super relevant in that context.
The authors are well-known experts on this particular disease and ancient DNA in general.
Not necessarily, but a common style recommendation is "avoid using the word 'black' to refer to anything negative or harmful" -- not because it is racist but because it might be misconstrued as such.
If I was a disease, then reacting to circumstance of a trade route, I would hope my gene expression and natural selection helped me: I want to survive on trade goods, in food, in a host animal (without killing it too soon) and "flow" along a path, which in human scale for the time takes months, if not years to move.
Plague looks to have hit the spot: it does kill, and it does cause horrific sequelae, but it also survives long enough to spread.
Bubonic/Pneumonic expression probably helps, two forms means two vector-paths. Host of rats/fleas, well rats are pretty hardy, adaptable, and good at both hiding and breeding rapidly. So they can carry long distances in trade goods, and then bust out to exploit local food sources. Or, just move alongside the trade goods by chance, following the inadequate hygene of the road/river camps. (obviously, hiding on boats also works but the silk road was predominantly a land route)
Nothing those pesky humans did was going to interfere until two things happened: they learned some basic hygene, and they learned a couple of low-bar tricks to immunise, and then finally they invented antibiotics.
But I probably have a trick or two up my sleeve to fight back. Lets start with "helping" them make antibiotics less reliable, and then lets think about other strategies..
If you were an infection that wanted to survive and spread as far as possible, you wouldn't want to kill your host at all.
In fact, if your host lives for as long as possible without suffering any negative effects from your freeloading, is preferred by mates and most loved by peers, etc., that's when you spread the furthest.
Seeing it as a nefarious plot to kill as many as possible (by prolonging incubation periods, etc.) is humans thinking in terms of how their species behaved in the past. In fact there is only maladjustment.
Sure, its maladapted where the common cold virus is much better adapted, and the bacteria which live in our stomachs are the best adapted of all: they just co-opted us as hosts.
But, along the road to perfect is good enough: If you can get along the silk road, you're doing ok.
> In fact, if your host lives for as long as possible without suffering any negative effects from your freeloading, is preferred by mates and most loved by peers, etc., that's when you spread the furthest.
Sure, that's one example:) Wouldn't say it is trying especially hard to make its host survive the longest (motorcycle accident anecdata and such) but it surely isn't killing it too fast.
Worth noting, seeing as it evolved to survive by cats and rodents, it is probably accidentally well-adjusted to humans (luckily we are not super different from rodents I guess). If it was as infectious as flu and had similarly mild effects it has now I'm sure most would be having it.
I wonder if some of the "worse" diseases are similarly mild to their animal hosts (birds and such), and us humans are just not as lucky to be similar enough in relevant aspects as with rodents and toxoplasma.
It changes both your appearance and behaviour to literally make you more attractive, but at the same time less fit depending on what you count. Also, it may be connected with schizophrenia.
Not to make me attractive. To make rodent get eaten by a cat. Supposed attractiveness of humans with latent toxoplasmosis is an accidental side-effect, since it does not transmit between humans it is entirely pointless.
> If you were an infection that wanted to survive and spread as far as possible, you wouldn't want to kill your host at all.
You may be oversimplifying here... consider that the host has an immune system and the infection has a limited time to either live in the host or to kill the host and remain in an infectious corpse for a while longer afterward.
I mean, somehow toxoplasma seems to not be caught by the immune system, so presumably they can evolve this way. If you don't directly harm the host, and maybe even benefit it, its immune system would have bigger fish to fry than going after you, no?
As to corpses, fair enough. Ah, if only these infections caught up that humans don't often just leave bodies around...
There was the first plague pandemic which began in 541 AD and brought done (or was one of the primary causes) the Roman Empire and lasted for several hundreds of years untill it died out (just like the second plague pandemic).
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[ 0.20 ms ] story [ 86.3 ms ] threadhttps://en.wikipedia.org/wiki/List_of_epidemics
https://en.wikipedia.org/wiki/Plague_of_Justinian
Condensed version:
"People who died in a fourteenth-century outbreak in what is now Kyrgyzstan were killed by strains of the plague-causing bacterium Yersinia pestis that gave rise to the pathogens responsible several years later for the Black Death, shows a study of ancient genomes."
"Other evidence puts the origins of the Black Death in this part of Central Asia. Among modern strains of Y. pestis bacteria, those sampled from marmots and other rodents in Kyrgyzstan, Kazakhstan and Xinjiang in northwest China, surrounding the Tian Shan mountain range, were most closely related to the Kara-Djigach strain. 'We can’t really say it’s that village or that valley, but it’s likely that region,' says Krause."
"[Miscellaneous scholar] is less sure of the study’s conclusion that the plague’s ‘big bang’ occurred around the time of the Kyrgyzstan deaths in 1338–39. Green has hypothesized, on the basis of genetic evidence, that the thirteenth-century expansion of the Mongol Empire catalysed the spread and diversification of Y. pestis strains responsible for the later Black Death."
"Where is Kyrgyzstan":
https://www.google.com/maps/place/Kyrgyzstan/@36.2729637,68....
> “When you have one or two years with excess mortality, it means something funny is going on there,” Slavin said at a press briefing.
When you have more than a couple of years of 'excess mortality' the ratio of tombstones to deaths may also decline. That's why we also look for mass graves. They can contain people nobody wants to bury (eg, dead Vikings after a failed invasion) or people nobody can bury.
An unusually high number in 1338 and 1339 may indicate a two year plague, or that people gave up it 1340.
1. https://www.theatlantic.com/science/archive/2018/12/4900-yea...
The authors are well-known experts on this particular disease and ancient DNA in general.
[1] https://my.clevelandclinic.org/health/diseases/21590-bubonic...
Plague looks to have hit the spot: it does kill, and it does cause horrific sequelae, but it also survives long enough to spread.
Bubonic/Pneumonic expression probably helps, two forms means two vector-paths. Host of rats/fleas, well rats are pretty hardy, adaptable, and good at both hiding and breeding rapidly. So they can carry long distances in trade goods, and then bust out to exploit local food sources. Or, just move alongside the trade goods by chance, following the inadequate hygene of the road/river camps. (obviously, hiding on boats also works but the silk road was predominantly a land route)
Nothing those pesky humans did was going to interfere until two things happened: they learned some basic hygene, and they learned a couple of low-bar tricks to immunise, and then finally they invented antibiotics.
But I probably have a trick or two up my sleeve to fight back. Lets start with "helping" them make antibiotics less reliable, and then lets think about other strategies..
In fact, if your host lives for as long as possible without suffering any negative effects from your freeloading, is preferred by mates and most loved by peers, etc., that's when you spread the furthest.
Seeing it as a nefarious plot to kill as many as possible (by prolonging incubation periods, etc.) is humans thinking in terms of how their species behaved in the past. In fact there is only maladjustment.
But, along the road to perfect is good enough: If you can get along the silk road, you're doing ok.
Mitochondria would like a word… I mean, almost all eukaryotes have 'em.
Ah, you mean toxoplasma gondii. Heh.
Worth noting, seeing as it evolved to survive by cats and rodents, it is probably accidentally well-adjusted to humans (luckily we are not super different from rodents I guess). If it was as infectious as flu and had similarly mild effects it has now I'm sure most would be having it.
I wonder if some of the "worse" diseases are similarly mild to their animal hosts (birds and such), and us humans are just not as lucky to be similar enough in relevant aspects as with rodents and toxoplasma.
You may be oversimplifying here... consider that the host has an immune system and the infection has a limited time to either live in the host or to kill the host and remain in an infectious corpse for a while longer afterward.
As to corpses, fair enough. Ah, if only these infections caught up that humans don't often just leave bodies around...
Is it possible that it only infected animals at first and only later find a way to infect humans like Monkeypox or SARS-CoV-2?