I have read that this is related to the end of the last ice age. Africa was apparently the continent which was least affected by melting of European and North A

I have read that this is related to the end of the last ice age. Africa was apparently the continent which was least affected by melting of European and North American ice sheets. North America and Europe underwent dramatic climate change as several hundred feet tall ice sheets covering large parts of the land mass melted and temperatures rose suddenly which would explain why megafauna went completely extinct in NA/Europe. Then there is also human factor of hunting these animals for meat and leather but it was probably a combination of factors.