The Garamantes joined a trade system they did not start

The Garamantes lived in the central Sahara, in what is now southwestern Libya, and scholars have often credited them with setting West African commerce in motion. The dates do not allow it. They became prominent from the ninth and eighth centuries BCE onward. By then two separate commercial revolutions had been running for centuries, one to the north around the Mediterranean and the Middle East, the other to the south across the western and central Sudan belt, each with its own towns, goods and merchants. The Garamantes sat on the southern edge of one and the northern edge of the other. They responded to what was already moving, took the profits of position, and in time began producing goods of their own for both markets. That is a real achievement and it belongs to them. Handing them the invention of the trade is a different claim, and it collapses as soon as anyone lines up the centuries. It is like crediting a ferryman with the river.

Hispaniola had ground sloths, large slow herbivores of a kind that had vanished from most of the Americas thousands of years earlier. Archaeological evidence places them still living in the Cordillera Central, the mountainous spine of the island, during the second millennium BCE and as late as roughly 800 BCE. They survived in the interior long after the coasts were settled. What ended them appears to have been the people. Rouse connects the extinction to the development of Courian hunting technology, a set of improved stone tools that made the highlands worth working. Once the interior could be hunted efficiently, a slow animal with no experience of predators had a short future ahead of it. This is the earliest documented case of human beings changing the ecology of the island that became Haiti and the Dominican Republic. The pattern set here, of an interior resource used until it is gone, repeats on the same mountains three thousand years later with the trees.

Around 700 BCE the knowledge of iron smelting began moving out from the early Great Lakes Bantu to the rest of the early Mashariki, the eastern branch of Bantu speakers. The Great Lakes region is where Schmidt and Avery documented prehistoric smelting of an advanced kind, and it acted here as the transmission node, the place from which furnace technique travelled on to communities spread across a wide stretch of eastern Africa. Ehret dates that stage from the linguistic and archaeological record together. He first set the finding out in a lecture at Columbia University in September 1974, added evidence from South Sudan when the Society of Africanist Archaeologists met at UCLA in March 1992, and published it later still. Nearly two decades separate the finding from the article. I keep the delay in view because it says something about the discipline. The resistance to African technical achievement that Schmidt later wrote about was already in the rooms where these papers were read.