Comment by ceejayoz
4 days ago
> It's curious how megafauna extinctions coincide with human arrival... Native Americans, Australian Aborigines, and other "First Peoples" were just as deadly as later European settlers.
That's one possible, maybe even likely scenario.
But humans started moving around at that time for a non-human reason; the end of the Ice Age. There's some evidence for populations of large mammals dying out before humans are believed to have showed up in those places, like Australia.
(As with most changes of this magnitude, the true answer is probably "more than one thing".)
Also, we tend to think of human effects and the change in climate to be mutually exclusive, but even if the end of the ice age had zero effect on the ability of megafauna to eat or reproduce, and an increase predation from the introduction of humans was the sole cause of their extinction, the presence of those humans itself would be an effect of the ice age ending.
These animals survived multiple climate changes before that. Nope, it was humans.
We're the reason the North American continent has _no_ large predators except bears.
Again, it’s probably both.
We humans nearly bought it during the same period; we bottlenecked at ~1,000 individuals for millennia. https://www.science.org/doi/10.1126/science.abq7487
The other hominins didn’t make it.
By your argument, if a species survives multiple climate changes it can never go extinct /except/ by human intervention.
Not true.
Sure. A couple of species will go extinct.
But somehow ALL the megafauna in Australia, Asia, and North America went extinct at approximately the same time humans arrived.