Comment by hearsathought

> It's curious how megafauna extinctions coincide with human arrival... Native Americans, Australian Aborigines

Native americans and australian aborigines arrival coincided with drastic climate change. Or put another way, climate change was a major driver of human migration.

> were just as deadly as later European settlers.

Unless natives and aborigines had guns, railroads, mass farming, etc, I highly doubt it. Not to mention the population boom due to modern medicine and mass migration.

If you consider the relatively small native american and aborigine populations, the technology involved and how gigantic america and australia is, it's absurd to think natives or aborigines wiped out the megafauna.

Species extinction has two major causes - climate/environment change and loss of habitat. Were the natives and aborigines sophisticated enough to cause climate/environment change or develop farming to a degree that deprived the megafauna of their habitats? I highly doubt it.