For the OP( and others that might be interested ), you might want to read this survey article from 1993 by Linda Newson on the demographic collapse in the Americas. It’s the best summary I read back in the day, though I’m a decade or two behind on current research . In short it was multi-factorial and varied a great deal depending on geography and in time( and related cultural issues, degrees of economic exploitation, etc. ).
This was a pet topic for me at one time, but I’m manfully resisting nitpicking some of the above posts :p. But in general, I think in aggregate Wesley Clark you’ve gotten the right answer already, in short:
-It’s Old World vs. New World disease, not European vs. everyone else.
-Native populations weren’t completely extirpated everywhere( they were in some areas ), they just underwent a horrendous decline. Eventually some very partially recovered. About 25% of Peru’s population still speak some variant of Quechua for example and unlike Guarani in neighboring Paraguay, those are mostly not dialects that have spread that far outside of indigenous populations.
But I think it’s a reasonable shortcut to say European in discussions of this topic. The diseases may have existed in Africa and Asia as well but it was Europeans who transmitted them to the Americas and other isolated areas.
This is strong evidence against the theory that the Chinese visiting America in the 15th century. If they had, they would have brought the same diseases that the Europeans brought. But there’s no evidence of any massive death toll in the Americas prior to Columbus’ arrival.
Correct. A large number of the immigrants/refugees we see from Central America are partly to completely indigenous. For many, Spanish isn’t even their first language but we Norte Americanos pathetically lump them all together as Latinos without questioning the designation.
Uh, I think you have this disease thing backwards. The Africans, being the oldest, have the strongest immune systems. The diseases that decimated the new world had previously done the same thing to Europe. The African immune system gives them more protection than any other group. The American Indians were all from a very small and recent group of Asians and they have the smallest innate immune system of all the major groups. They had the least ability overcome the traditional diseases that suddenly arrived with the Europeans and Africans.
If I am not explaining the immune system correctly, I apologize, it isn’t my area. I am referring to the innate immune system. As I remember it, There are about 7 components of the innate system. Each one provides the body with the ability to fight off lots of diseases. But not all. Sooner or later everyone is exposed to a disease their particular set of components can’t deal with. Then you had better hope that your adaptive immune system can cope. But it isn’t as effective as the innate system. Few people if any have all 7. Africans, having been at this the longest, have the most. Perhaps 4 or 5 in any individual. These are inherited. Each person in each generation has some mixture of available components from their parents. If they are lucky they will fight off the next new disease. If not, their neighbor might. As the number of components available to the population decreases, each new disease may be devastating. Europeans and Asians have fewer components than Africans. Native American Indians have fewer still. Again, that is as I understand the process. I could be messing it up, but the idea is that American Indians have fewer innate components than “older” more diverse populations. It isn’t all bad. Native Americans also don’t have several inherited diseases that the rest of us suffer with.
However, one way they “transmitted” them was by importing slaves from Africa that brought in tropical and sometimes other diseases. Notably, the smallpox epidemic that swept through the Aztec Empire during Cortes’s invasion, making his conquest easier, seems to have been brought to Mexico via an African slave coming from the West Indies.
And it shows, you have it wrong. Disease resistance in populations is a function of what diseases have those populations been subject to previously (which doesn’t mean “years ago and not any more”, it means anybody born there is subject to them): most people from Africa, Asia and Europe were resistant to Old World diseases which caused high mortality in the New World because they were exposed to them. The Old World exceptions (MrDibble mentions one, the Khoe-khoen) are peoples who hadn’t previously been exposed to whatever the disease was. The Black Plague was deadly because the populations it reached hadn’t been exposed to that particular bacillum before: once enough people developed resistance to the bacillum, the Plague ended. New World diseases killed Old World people merrily, independently of where these Old World people had been born, on account of these people not having been exposed to them before. Exposure and disease resistance have got nothing to do with the length of people’s family tree.
Over 98% of Spaniards are TB positive. Incidence of actual TB in Spain is below 1%, and limited to immigrants who have previously received no medical care in their whole life. The TB test checks whether someone has TB antibodies: we have them precisely because we’ve been exposed to the TB baccillum and our bodies have responded correctly, creating those antibodies. We’re all exposed to TB now, despite most of us having never met a person who had actual tuberculosis in our whole lives. That’s what’s meant by “prior exposure”: in our lifetimes, not in those of our ancestors.
Little to add other than that my impression (from quite a bit of reading) has also been that a great portion of indigenous populations had succumbed from imported diseases prior to 17th century colonization in Virginia and Massachusetts.