Today, it’s a widely accepted fact that humans originated in Africa. But less than a century ago, anthropologists assumed that Eurasia was the birthplace of humanity. And scientists held onto that mistaken belief until one man took a stand that rewrote history.
In 1923, Raymond Dart arrived at the University of the Witwatersrand in Johannesburg to take a post as the head of its anatomy department. The 30-year-old Australian physician, an expert in neuroanatomy, was disappointed to learn that the university did not own a reference collection of bones and fossils. He set out to amass one, offering his students a prize for the most interesting bones they could find. His lone female student, Josephine Salmons, soon presented him with a South African fossil that would lead to the discovery of a lifetime. The fossil, a baboon cranium, sparked Dart’s interest, since only two primate fossils had been found in sub-Saharan Africa until then. Salmons had found the fossil at the home of the director of the Northern Lime Company at Taung, a mining site in South Africa. Dart asked the manager of the site to alert him to any fossils that his miners unearthed in the future.
One Saturday in 1924, two boxes of rocks from Taung were deposited at Dart’s door. In the second box, he came across an exciting find: an endocast, the fossilized imprint of an animal brain. To his astonishment, the endocast showed a brain larger than that of a chimpanzee but smaller than those of known human ancestors.
Digging through the box, Dart located the matching limestone rock that he knew might contain the face to match the brain. His thoughts turned to Charles Darwin, who, in his 1871 book The Descent of Man, predicted that humans’ earliest apelike ancestors would be discovered in Africa because our closest ape cousins—chimpanzees and gorillas—lived there. Darwin’s prediction had been generally discredited. After all, only two ancestral human fossils had ever been found in Africa and both were relatively recent, closer to modern humans than to apes. Dart wondered whether he had stumbled upon proof of Darwin’s controversial theory.single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.