Our first steps? Fossil may boost case for earliest ancestor

In this photo provided by the University of Poitiers in August 2022, researchers Franck Guy, left, and Guillaume Daver sit together at the PALEVOPRIM laboratory in Poitiers, France. Based on arm and leg fossils, scientists concluded that Sahelanthropus, an ancient hominin species from Chad, walked upright - which would add evidence that it’s the earliest human ancestor dug up so far, according to a study published on Wednesday, Aug. 24, 2022, in the journal Nature. (PALEVOPRIM/CNRS – Universite de Poitiers via AP)