Charles Darwin knew humans evolved from apes, but he died before the strongest fossils that prove our connection with primates had been discovered.
In The Descent of Man he wrote, “Those regions which are the most likely to afford remains connecting man with some extinct ape-like creature, have not as yet been searched by geologists.”
A century later, Lucy helped confirm Darwin’s conjecture. By that time, a vision of our origin had been born, and her skeleton was assumed to fit the story. It’s one that (wrongly) persists today: Apes climbed out of the trees and ambled onto their feet, dragging their fists, as the climate warmed and turned forests into grasslands. Yet it was clear to paleontologists that many more fossils were needed to test this hypothesis. That’s around when Ethiopian paleontology by Ethiopians got started in earnest.
The bones of distant members of our human family are buried in tumbles of sand in Africa, and Ethiopia has unbeatable archives. The pages of human prehistory are preserved in its layers of mud, bones, and basalt. In the Afar, the magma that periodically bubbles to the surface serves as a timepiece because the chemical composition of every volcanic rock betrays the stone’s age. Over time, the ratio of the gases trapped within it changes at a fixed, known decay rate, so you can determine whether it covered the land 4 million years ago or yesterday. Fossils located between two layers of volcanic ash and lava were left by animals that lived within that time range. Individuals belonging to Lucy’s and Salem’s species have been found in layers dating from almost 4 million to 3 million years ago. That means they lasted five times the duration of our own species so far.
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“Can we do at least as good as this primitive species?” Alemseged asked.
Read full original article: Digging Through the World’s Oldest Graveyard
