Losing the plot

Abstract

Barras finds out who were the humans' ancestors and where they came from. Once upon a time, the human story seemed relatively straightforward. It began roughly 5.5 to 6.5 million years ago, somewhere in an east African forest, with a chimpanzee-like ape. Some of its descendants would eventually evolve into modern chimps and bonobos. Others left the forest for the savannah. They learned to walk on two legs and, in doing so, launched their own hominin lineage. By about 4 million years ago, the bipedal apes had given rise to a successful but still primitive group called the australopiths, thought to be the humans direct ancestors. In the early 2000s, the standard story of how H. sapiens evolved from a chimp-like ancestor seemed linear and logical, then came 15 years of relentless and confounding discoveries.