system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why is Africa the least developed continent if humanity started there?
gpt
Well, you can contrast Northern Africa from Southern Africa. For most of history, Northern Africa wasn't any less developed than the most developed parts of Europe or the Near East (although it fell behind in the early industrial period).

In fact, Carthage and Egypt were among the wealthiest, most advanced civilizations in multiple eras right up through early modern times.

The difference between North Africa and the rest of the continent? The Sahara Desert is a giant, awful sinkhole that killed 99% of cultural exchange or trade relations between most of sub-Saharan Africa and the outside world, except for some contact in and around the ports - which more often resulted in slave trading than productive cultural exchanges.

Isolated cultures pretty much never do well on the scale of human development.