A new study published in Nature describes the discovery of 13 fossilized teeth from the Ledi-Geraru site in Ethiopia. They have been dated to between 2.6 and 2.8 million years ago and are attributed to two distinct hominin species: early Homo and a newly identified Australopithecus relative.¹ The researchers argue that this find supports a “bushy tree” model of human evolution, where multiple species lived side by side rather than evolving from one to another in a straight...