A deadlier Columbian exchange

I'm aware that Cash made a thread very much like this one, but I don't know what the policy on necro-ing old threads are, so I'll make another one.

As we're all aware, a cocktail of diseases devastated the American continent after contact between Europeans and Americans. What if there were also native diseases to which the Europeans didn't have as strong an immunity? Say that by the end of the 16th century, 80% of European colonisers have have set foot on the continent are dead. How would history have changed with such a high mortality rate?

What if the diseases crossed the Atlantic and struck Europe?
 
Not very likely. Most diseases are born out of human-animal interaction, and to put it simply there just weren't a lot of areas in the Americas where people were working with domesticated animals on a day-to-day basis.

Much more likely, and thought provoking, could be the affect of more European diseases making it across the Atlantic, and killing or disabling more natives.
 

archaeogeek

Banned
There were some diseases that did kill the conquistadores and some colonists in the Andes, but the problem was that they had a very short incubation period, iirc too short to even realistically affect the colonies on the Main. You'd need something with a much longer incubation period that won't massacre the colonists outright before they have the time to hop back on a ship...
 
Syphilis.

And does smoking counts?

The issue with smallpox-like diseases is that the sick Europeans must remain alive during the journey back to Europe - and not be killed by the rest of the crew if the crew thinks they can transmit a deadly disease to them.
 
The big problem is that any scenario which gives the Americas a nice milieu of native diseases also changes the Americas in innumerable other ways.
 
What if you had something like malaria, which has many natural reservoirs? People who get a mild case are able to keep on spreading it as long as there are mosquitoes, and it could become a chronic infection. Maybe a more virulent form of Leishmania braziliensis that is capable of being spread through mosquitoes will work. AFAIK, malaria and leishmaniasis don't require constant close interaction with animals to become able to attack humans because most mammals work as hosts. Europeans who live in close quarters become easy prey to infected mosquitoes. The disease will still be restricted to the warmer parts of Europe as well as Africa and Asia, but it could be serious enough to alter events. Malaria was certainly a problem around the Mediterranean until relatively recently.
 
AFAIK, malaria and leishmaniasis don't require constant close interaction with animals to become able to attack humans because most mammals work as hosts. Europeans who live in close quarters become easy prey to infected mosquitoes. The disease will still be restricted to the warmer parts of Europe as well as Africa and Asia, but it could be serious enough to alter events. Malaria was certainly a problem around the Mediterranean until relatively recently.
No, malaria, at least, is pretty specifically human, or at least related primates. Chimpanzees, for instance, have a different form of malaria.


One PoD might be that American malarias jumped to humans (which would be difficult, but not a huge stretch).

The problem is that Africa is where humanity evolved, and Africa is where most human infecting diseases come from. Thus, outside Africa, a disease has to jump species barriers, which is certainly possible., but is really, REALLY aided by domestication where the humans and animals are in direct proximity.
 
No, malaria, at least, is pretty specifically human, or at least related primates. Chimpanzees, for instance, have a different form of malaria.


One PoD might be that American malarias jumped to humans (which would be difficult, but not a huge stretch).

The problem is that Africa is where humanity evolved, and Africa is where most human infecting diseases come from. Thus, outside Africa, a disease has to jump species barriers, which is certainly possible., but is really, REALLY aided by domestication where the humans and animals are in direct proximity.

I agree with your overall point, which is that nasty New World diseases for humans are less likely than old world ones, for the reasons you mentioned and also because cities were a more recent phenomenon in the New World by a good many thousands of years.

I sort of disagree about malaria. I'm 90% sure that there were no malaria species in the New World pre-Columbus and that malaria jumped from humans to New World monkeys after Columbus. It evolved into a new species or at least a subspecies in New World monkeys in the last several hundred years. New World monkeys are genetically quite distinct from Old World ones, isolated for 25-30 million years.

Btw: (and this actually has AH potential) it appears that a particularly nasty kind of monkey malaria in Borneo is 'gearing up' to jump to humans. It's infecting people who are in close proximity to the monkeys, but probably not doing human-to-human transmission routinely at the moment.
Monkey malaria

In terms of the overall subject: In my American Indian Victories book I have a scenario where a virus lurks harmlessly in Indians (and Europeans who have not had smallpox), but causes an autoimmune disease among people who have an immune response to smallpox that destroys their joints and leaves them helpless with the equivalent of crippling arthritis. Not likely, but it is a way around the dilemma of "if Indians had dangerous diseases to give the Europeans they wouldn't be the historical Indians". I also have a scenario where a nasty disease jumps from some common rodent to horses, leaving the conquistadors on foot. That's actually more plausible, and it would make it very difficult for the Spanish to take down the Aztecs or Incas.
 
You can have a Pacific Exchange with black death on 13th century just have avoid the Mongol Empire expanding East wards and expand in Kamchatka and Alaska in that way europe is not immune to black death...but that will cause a deadly columbian exchange.
 
Last edited:
I agree with your overall point, which is that nasty New World diseases for humans are less likely than old world ones, for the reasons you mentioned and also because cities were a more recent phenomenon in the New World by a good many thousands of years.

I sort of disagree about malaria. I'm 90% sure that there were no malaria species in the New World pre-Columbus and that malaria jumped from humans to New World monkeys after Columbus. It evolved into a new species or at least a subspecies in New World monkeys in the last several hundred years. New World monkeys are genetically quite distinct from Old World ones, isolated for 25-30 million years.
Hmmm.... Looks like you're right. I had understood otherwise, but a phylogeny I found
http://tolweb.org/Plasmodium/68071 said:
groups both P.simium with the human P.vivax and P.brasilianum with the human P.malariae.

Thank-you.
 
The easiest way in my mind is to create a situation where Polynesians arrive in the Americas with chickens and pigs, and then go on to create a number of diseases as they spread throughout the Americas. The Polynesians either got to the Americas or came very very close so it's not a big change really. Of course everything will be totally different in the Americas, but it does work I think.

Considering that the average death rate of something like the Bubonic Plague was 60% on virgin ground this world would be... very depressing.
 
The easiest way in my mind is to create a situation where Polynesians arrive in the Americas with chickens and pigs, and then go on to create a number of diseases as they spread throughout the Americas. The Polynesians either got to the Americas or came very very close so it's not a big change really. Of course everything will be totally different in the Americas, but it does work I think.

Considering that the average death rate of something like the Bubonic Plague was 60% on virgin ground this world would be... very depressing.

Actually, if you want something that could jump back to the Old World you could have some kind of flu jump from chickens or pigs to humans in the New World shortly after the animals are introduced by your Polynesians. It could develop into a nasty strain in the New World, and then be ready for Columbus or whoever gets butterflied into discovering the New World. He takes it back to Europe with him and voila. The New World strikes back.
 
Actually, if you want something that could jump back to the Old World you could have some kind of flu jump from chickens or pigs to humans in the New World shortly after the animals are introduced by your Polynesians. It could develop into a nasty strain in the New World, and then be ready for Columbus or whoever gets butterflied into discovering the New World. He takes it back to Europe with him and voila. The New World strikes back.
Yeah, that's what I meant, sorry if I wasn't clear.
 
Top