[jimtorr]

......they cleared land for farming and iron smelting.

I don't know if the population would have been large enough to have a significant impact on rain forest, but 4,000 years ago seems early for iron smelting. The Iron Age is generally accepted to have begun about 1200 BC.

[Flag_This]

"but 4,000 years ago seems early for iron smelting."

Great catch. 4,000 years ago is the end of the Neolithic, not even Bronze Age yet.

[SunkenCiv]

The article states that the Bantu expansion started 4000 years ago, and their iron smelting as an activity started some unspecified period of time after that.

Also, iron smelting may have originated in Sub-Saharan Africa around 2000 BC. The earliest known cast iron is from about 800 BC (China).

The use of meteoritic iron began quite a long time ago.