system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it that Africa is the only continent to have kept it's native megafauna preserved throughout the ages while most other continents (Australia, Europe, North America) have lost theirs?

Especially Australia, I read somewhere that nearly half of it (if not more) is virtually untouched wilderness. Has climate change and aboriginal hunting seriously done that much damage? I mean i always wonder why Australia is practically covered by modern kangaroos while *Procoptodon goliah* didn't make it despite the main difference is being just a metre and a half taller than the common red. If there has been settlement in Africa for so long why haven't rhino's, elephants, and hippos died out yet? I write this question with a hint of annoyance that such a unique arsenal of organisms had to disappear. The fact that Thylacoleonids (some of the most unique and powerful predators to have ever walked the earth), as a family are extinct frustrates me greatly because I wish i would've had the chance to witness such predatory prowess, especially when i realise that the Thylacine went extinct less than a century ago! Also, please forgive any present ignorance i have on natural history, I'm only 17 haha. 


edit: I understand climate change has drastic effects on fauna, but my main question relates more to the preservation of Africa's megafauna while Australia has lost it's giants despite not experiencing a glacial period since permian times.
gpt
Because African megafauna evolved in parallel with humans.  They have had to cope with each other for millions of years, and so are in a kind of balance.  Once humans left Africa they found megafauna which was not adapted to humans and human hunting, and wiped them out.  This is particularly true of Australia which is a relatively energy-poor ecosystem and did not have large apex predators.  Once humans arrived it is theorised that they eliminated various large herbivores, allowing kangaroos to thrive.  As a side note  these large herbivores were responsible for eating a lot of leaf litter in forests, and when they were gone these areas became prone to bush fire. Aboriginal Australians developed "fire stick farming" (controlled burning) as a way of preventing catastrophic fires as well as promoting habitat for kangaroos, which were a significant food resource.