Wikipedia shows 55 million, but this article https://www.scientificamerican.com/article/amazon-rainforest... reads at 2000 years old.

These are orders of magnitude different. Maybe they are using different definition or sub-regions.

The article also says:

>The arrival of European diseases after Columbus crossed the Atlantic in 1492 may also have hastened the growth of forests by killing indigenous people farming the region, the scientists wrote in the U.S. journal Proceedings of the National Academy of Sciences (PNAS).

It would be very lucky for humans to be so devastating[1] to the natural environment everywhere except the Amazon and yet have been excellent stewards of the natural environment within the Amazon. Such assumptions smack of the "noble savage" mythology.

1: https://en.wikipedia.org/wiki/Quaternary_extinction_event

I think humans were more devastating to the environment elsewhere (e.g. in Europe) simply because there were more humans there. Also, tropical rainforests are not really comparable to forests in temperate regions. So my theory is that the faster-growing forest and the lower population density protected the rainforest of South America (and also equatorial Africa) until the 20th century.

In my opinion humans are worst thing for environment, Direct human causes of deforestation include logging, agriculture, cattle ranching, mining, oil extraction and dam-building. https://www.mybalancenow.tips/

In my opinion humans are worst thing for environment .Direct human causes of deforestation include logging, agriculture, cattle ranching, mining, oil extraction and dam-building.

a common pattern that follows human spread is called "broad spectrum revolution". Often they'll make it to a new place, feed off the present megafauna until they, oftentimes, run it to extinction, and then are forced into a BSR and we see the development of more complex landscape management techniques, hunting of much smaller game, technologies like pickling/preserving, domestication of more plant species, etc. Cultures too are subject to this form of evolution. You often see cultures very explicitly dedicated to the protection of caretaking of their environments where there are traces of extinct megafauna. The peoples of the NE woodlands of North America for example had their entire tribal identities centered around certain animals they were in charge of protecting (while still hunting and living off them)

well I suppose it depends what you define as the starting point but it's generally recognized it began in the Eocene epoch (55.8 million years to 33.9 million years ago)

Not sure how that's relevant to the sentence you quoted though. The Amazon rainforest has been largely savanna type ecosystems at various points in its history. Including quite recently (like 12kya)