Since the turn of the millennium, our understanding of our ancestors and extended cousins has shifted dramatically, thanks to a swathe of surprising archaeological discoveries

Developments in the study of human evolution over the past 25 years can be captured in a single word: “more.” Archaeologists have uncovered far more fossils, species, and artefacts, spread across a wider range of locations than ever before—from the tiny “hobbits” of an Indonesian island to the enigmatic Homo naledi, known only from a deep cave in South Africa. At the same time, scientists have created increasingly sophisticated methods for analysing these remains. As a result, there is now an unprecedented volume of information about human origins and our extinct relatives.

From this surge of discoveries, two key insights have emerged. First, since 2000, the hominin fossil record has been pushed much further back in time. In the late 1990s, the oldest known hominin was Ardipithecus, dated to 4.4 million years ago. However, discoveries in 2000 and 2001 revealed even earlier species: Orrorin tugenensis, dating to about 6 million years ago, and Sahelanthropus tchadensis, which lived roughly 7 million years ago. More recently, a second Orrorin species, Orrorin praegens, was described in 2022 and appears to be slightly younger than O. tugenensis.

“These early hominin discoveries represent one of the major revolutions in the field,” says Clément Zanolli of the University of Bordeaux in France.