4 ms·

You're correct that some cities existed in the Americas on par or larger than most European cities (ie Teotihuacan). I don't know why people don't just chalk it

You're correct that some cities existed in the Americas on par or larger than most European cities (ie Teotihuacan). I don't know why people don't just chalk it up to an accident of viral/biological disease evolution. You could imagine an alternate timeline where the native Americans had survived similarly horrific incidents as the Justinian and Black Plagues, as well as Smallpox, but then Colombian exchange brought back the diseases to Europe. Maybe it was just an unfortunate coin flip of history. Maybe the racial diversity in the Eurasian-African land mass contributed to the disease diversity and acuity?

AlotOfReading 4y ago
If you just want my idle speculation, my personal guess is that diseases did exist in the Americas, but 1) we lack the ability to see them in the record and 2) the dynamics of how those diseases originated/spread is significantly different between afroeurasia and the new world. One of the problems with archaeology is that things have to be archeologically visible in order for us to realize they exist. Diseases usually don't leave skeletal evidence and many American cultures were big on cremation besides. It's only under very unique circumstances with certain diseases (e.g. the mummies with tuberculosis mentioned previously) that we can clearly see the evidence to say "hey, these people died in a disease outbreak". In Eurasia we rely heavily on literary sources to supplement this issue, but we have few American sources and they're mostly focused on other things. The nature of continents is also substantially different. The Americas were hugely affected by late quaternary extinctions that destroyed the mammalian diversity, a main factor in zoonotic transmission [1]. The places where that diversity exists post-LGM like the Amazon basin are very remote and their pre-Columbian history is not well studied, let alone the history of disease there. We have little understanding of how they integrated into broader American trade networks either. Eurasia's biodiversity is spread across large areas of the continent, which happen to be crossed by continental trade routes. If plague had originated in Venezuela instead of from rodents in central Asia, we might not even know about historical outbreaks and simply label it a new disease when modern farmers in the highlands caught it. [1] https://doi.org/10.1073/pnas.1919176117 https://doi.org/10.1073/pnas.1919176117
mcculley 4y ago
According to Wikipedia, Teotihuacan had an estimated population of 125,000 or more, "making it at least the sixth-largest city in the world during its epoch at its zenith", which is thought to be no later than 550 CE. Rome is estimated to have had 1,000,000 inhabitants around 0 CE. Certainly the Europeans had much greater population and density. How could they not be carrying around more virulent parasites?
- chrisco255 4y ago
  https://www.jetpunk.com/users/quizmaster/charts/population-of-rome-over-time https://www.jetpunk.com/users/quizmaster/charts/population-o... Rome's population collapsed dramatically after the fall of the empire, by the medieval period, Rome's population was 20,000. Even London didn't exceed 100,000 until the 17th century and most European towns were small villages with a few hundred to a few thousand at most. By my reading of history, the Americas were relatively better off than Europe for much of the dark and middle ages, in average health, height and even lifespan. They were probably at least as populous as Europe if not moreso. Teotihuacan was one of the largest cities in the world for much of the last 2000 years. Modern day Mexico City (25 mi from where Teotihuacan was) has 9 million to this day. There are also massive ruins of cities in the Amazon for which we know very little about from this era. The biodiversity is also incredible in the Amazon, so there could feasibly be many zoonotic diseases in those jungles. I'm partly playing devil's advocate here, I do think the racial diversity and intercontinental exchange in the old world contributed to it.
  - mcculley 4y ago
    I am aware that Rome’s population decreased. My reasoning is that a population that was larger and denser in the past is carrying around more parasites. Rome is just one example. By 1492, Europe had many large cities and lots of travel between them, enormously more population and travel than the Americas. They had a more fertile environment for parasites.

AlotOfReading 4y ago

If you just want my idle speculation, my personal guess is that diseases did exist in the Americas, but 1) we lack the ability to see them in the record and 2) the dynamics of how those diseases originated/spread is significantly different between afroeurasia and the new world. One of the problems with archaeology is that things have to be archeologically visible in order for us to realize they exist. Diseases usually don't leave skeletal evidence and many American cultures were big on cremation besides. It's only under very unique circumstances with certain diseases (e.g. the mummies with tuberculosis mentioned previously) that we can clearly see the evidence to say "hey, these people died in a disease outbreak". In Eurasia we rely heavily on literary sources to supplement this issue, but we have few American sources and they're mostly focused on other things. The nature of continents is also substantially different. The Americas were hugely affected by late quaternary extinctions that destroyed the mammalian diversity, a main factor in zoonotic transmission [1]. The places where that diversity exists post-LGM like the Amazon basin are very remote and their pre-Columbian history is not well studied, let alone the history of disease there. We have little understanding of how they integrated into broader American trade networks either. Eurasia's biodiversity is spread across large areas of the continent, which happen to be crossed by continental trade routes. If plague had originated in Venezuela instead of from rodents in central Asia, we might not even know about historical outbreaks and simply label it a new disease when modern farmers in the highlands caught it. [1] https://doi.org/10.1073/pnas.1919176117 https://doi.org/10.1073/pnas.1919176117

mcculley 4y ago

According to Wikipedia, Teotihuacan had an estimated population of 125,000 or more, "making it at least the sixth-largest city in the world during its epoch at its zenith", which is thought to be no later than 550 CE. Rome is estimated to have had 1,000,000 inhabitants around 0 CE. Certainly the Europeans had much greater population and density. How could they not be carrying around more virulent parasites?

chrisco255 4y ago
https://www.jetpunk.com/users/quizmaster/charts/population-of-rome-over-time https://www.jetpunk.com/users/quizmaster/charts/population-o... Rome's population collapsed dramatically after the fall of the empire, by the medieval period, Rome's population was 20,000. Even London didn't exceed 100,000 until the 17th century and most European towns were small villages with a few hundred to a few thousand at most. By my reading of history, the Americas were relatively better off than Europe for much of the dark and middle ages, in average health, height and even lifespan. They were probably at least as populous as Europe if not moreso. Teotihuacan was one of the largest cities in the world for much of the last 2000 years. Modern day Mexico City (25 mi from where Teotihuacan was) has 9 million to this day. There are also massive ruins of cities in the Amazon for which we know very little about from this era. The biodiversity is also incredible in the Amazon, so there could feasibly be many zoonotic diseases in those jungles. I'm partly playing devil's advocate here, I do think the racial diversity and intercontinental exchange in the old world contributed to it.
- mcculley 4y ago
  I am aware that Rome’s population decreased. My reasoning is that a population that was larger and denser in the past is carrying around more parasites. Rome is just one example. By 1492, Europe had many large cities and lots of travel between them, enormously more population and travel than the Americas. They had a more fertile environment for parasites.