[rogerthis]

Goat?

[Arubis]

You’re being downvoted, but there’s actually something to this theory. The spread of Islam throughout the African continent brought with it a cultural taboo against pork; pigs were mostly displaced by goats, which will frankly eat anything down to its roots.

[pvaldes]

Probably. And fire also. Desert can become chill at nigh so even if there aren't many trees you need some kind of wood to burn.

At some point the ecosystem just can't regenerate faster enough, the buffer is broken, and all is downhill from that point.