I’ve often heard that Europeans carried with them diseases such as small pox that would inevitably cause a great deal of death among any new civilization they came into contact with. Given the isolation between the civilizations this isn’t wholly unexpected. What I don’t understand is why the Native Americans or other groups didn’t have their own diseases to which they (the other groups) had become largely immune to and cause large scale disease among the Europeans.
In short, why were the deadly diseases mostly a one way transmission? One explanation indicated it was due to the difference in proximity to animals. Europeans herded animals and Native Americans didn’t. Is there any truth to this?
This is essentially the premise of McNeill’s Plagues and Peoples. Other factors are the extent of trade and interchange in Eurasia, the consolidation of populations into large metropolitian areas and resulting contact with sewage and contaminated waste, and the small genetic complement of the American natives as opposed to the much more diverse gene pool of the Eurasians.
One hotly debated theory is that syphilis was unknown in the Old World until Columbus’s crew brought it back with them, courtesy of the Native Americans. Syphilis-like symptoms are described in earlier European texts, but it’s debated as to which specif disease or conditions they refer to.
Yes. I also believe that it was because of the small populations in the New World. Without large populations contagious diseases cannot spread. Diseases like measles need a large population so that they can attack one area, then spread to another and later return to the original area and infect those that weren’t born during the first epidemic. May be why they are childhood diseases. A stronger bug may wipe out most or all people in the area, but then just die out.
That is why when a new serious disease starts we try to keep it localized.
There’s also the European proximity to many domesticated animals – dogs, cats, pigs, cattle, sheep, goats, horses, donkeys, chickens, rats* – which contributed to animal diseases crossing over into humans. The North American Indians had only the dog, and the South American Indians had only the llama/alpaca and guinea pig.
*Of course rats aren’t “domesticated” but they live among humans.
I believe there have been several excavations of native american remains exhibiting smallpox symptomatology dating to prior to the arrival of euros, and regarding NA to Euro transmissions, I believe that syphillus is the accepted evil actor?
Cite? I have never heard of this, and believe it to be incorrect.
Another factor for the Americas is that they had been colonized by (presumably) very small bands of people, and through their early history population densities were very low. These are poor conditions for the transmission and retention of contagious diseases in the population. Passage through or around the Bering Land Bridge may have largely “cleansed” the migrants of contagious diseases. Tropical diseases such as malaria or yellow fever also would not have been able to make the passage through arctic areas, where the mosquito vectors would have been absent through much of the year.
The whole ‘Europeans living with their domesticated animals’ deal was one of the premises for Guns, Germs & Steel by Jared Diamond. Sorry, dunno how to make a link.
According to him, there just weren’t any large animals to domesticate in the New World by the time domestication started taking place (the large animals having been killed off by the recently arrive humans). Which lead to less diseases jumping over to people, and combined with lower population densities, just didn’t create as many really killer epidemics as compared to Eurasia.
It’s worth noting that there are a couple of native New World nasties present that just didn’t make the jump back, almost certainly because of the biological limitation of their insect vectors. Chagas’ Disease, an American trypanosomyasis whose vector are blood-sucking Triatomine bugs, is probably the most prominent. Other members of the genus Trypanosoma cause “Sleeping Sickness” and “Nagana” in Africa - they also weren’t exported to Europe or Asia ( if they had they would have had an utterly devastating impact on history - Nagana kills horses dead, dead, dead ), because their vector, the infamous Tsetse fly, also doesn’t travel.
Rather more obscure is Carrion’s Disease, a form of Bartonellosis, transmitted by sandflies that only occur at certain elevations in the Andes. other members of the genus Bartonella cause Trench Fever and Cat-Scratch Fever ( but not the distantly related Nugentosis ).
Yep, there are any number of reasons, all contributing. In addition to those noted above the other important factor is travel. Eurasians travelled a lot, for trade and for warfare. The invention of the wheel and the domestication of draught and riding animals were very important, as was the development of maritime technologies. Indians never developed those technologies and as such tended to be stay-at-homes, mostly just killing, raping and swindling their neighbours while the Eurasians were more egalitarian and killed, raped and swindled people living thousands of miles away.
Every time people travel they have a really good chance to pick up interesting diseases and take them back home to share with freinds and family. Because Europeans travelled so far and so fast all of the landmass had been exposed to all the possible diseases. An embarssing rash appearing in Turkey was taken to Greece within days on a galley, or a plague in Afghanistan could be carried by fleeing refugees all the way to London via trade routes even if the initial victims all dieed within days. In contrast a disease that appeared in Peru might devestate one city, but it had no real way of spreading to New York. There weren’t any ships plying the coast of the Americas, nor were there any trade routes for refugess to travel along as they fled a plague.
So even if Americans had domesticated animals to give them diseases and a large starting gene pool they probably wouldn’t have fared much better. Diseases simply don’t jump species often enough to confer widespread immunity without dissemination within the new species. As a result people in one town in the Americas might be immune to one type of disease that had originated there but not to any of the others. When Europeans arrived they brought dozens of fatal and contagious diseases in one hit. The people in that town might have a genetic resistance to smallpox because of exposure to a similar disease and may survive, but when syphillis hit they had no resistance at all and promply died. The people in the next town might be immune to syphillis, but they would have already all died from smallpox.
It isn’t enough to just have genetic resistance to one disease, a population needs to have resistance to a wide spectrum of diseases to survive that sort of event, and a lack of travel meant that this wasn’t possible in the Americas. Basically the Americans were doomed on all levels. No sources of disease, a small genetic pool to select from and no means of distributing disease to ensure that all populations had exposure to novel diseases.
What? No obligatory * Guns, Germs, and Steel* reference? C’mon, people, this thread is already 10 posts long!
Diamond pretty much asked the same question as the OP. His thesis is pretty much what people have already said; higher population densities coupled with a close proximity to a variety of domesticated animals generated a heady stew of infectious diseases that the populace eventually grew immune to. This worked to the Europeans’ unwitting advantage when the two cultures met.
As regards syphilis, Diamond notes (page 210) that syphilis was first definitively recorded in Europe in 1495…interesting date, non?
It’s not quite as simple as large populations. Aborigines in Northern Australia were at least as genetically resistant to smallpox, measles and other diseases as Eurasians are, while Aborigines in Southern Australia at much higher population densities were decimated.
The difference was the number of contacts. Northern Australians were subjected to frequent contact with Asia for millennia, and annual contact for centuries. By the time Europeans arrived the population had been repeatedly infected, decimated, recovered, infected by something else, decimated, recovered etc. The addition of Asian genes probably helped, but if the contact had been infrequent or a one-off then the population would have been decimated and rapidly replaced by uninfected and unresistant people from elsewhere. No genetic resistance could result no matter what size the population was initially.
The problem with European contact in the Americas and Southern Australia was that contact and infection was rapidly followed by invasion and subjugation. The populations never had a chance to develop genetic resistance no matter how large they were. Had the Europeans never invaded but just returned to trade every 50 years or so the population could have recovered and established its own genetic resistance.
It’s not the bug that has changed, it is the host. The reason they are childhood diseases is that any individual who was genetically disposed to being killed has left no descendants. The only Eurasians left alive are those whose ancestors could resist the strongest bugs when infected as children. As a result most Eurasian children will survive the worst forms of those bugs.
We can tell that the bug hasn’t changed by looking at what happens to naïve host populations that are exposed. Americans and Australians were decimated by measles, mumps, rubella, herpes and even the common cold. The only people who left descendants were those who could cope with that onslaught. And to their children the bugs were also just childhood illnesses that were usually not fatal.
The bugs remained unchanged and every bit as fatal as ever for millennia in Eurasia. It was the host population that had evolved to resist the bug, not the bug that had evolved to be less fatal. The same bug in a naive population had the same fatal effects it doubtless had when it first arose in Eurasia.
Another possible factor is that the Europeans were going to America not vice versa. If some Europeans had a disease they were resistant to they brought it to America and infected the Americans they met. But consider the opposite possibility; if the Americans had a similar disease they might infect and wipe out a settlement of Europeans but the disease would not be transmitted back to Europe itself. Obviously, some diseases were slow acting enough to be transmitted across the ocean in either direction but the big killers like smallpox that would kill off an entire population were limited in their potential to travel.
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