Humans, Homo sapiens, can trace the origins of our genus Homo back almost 3.0 million years. The earliest evidence for the emergence of our genus is a 2.8-million-year-old partial jaw bone, a mandible, from Ledi Geraru, a paleontological site in northern Ethiopia. This mandible, LD 350-1, has features that resemble some of the younger Homo specimens and differentiate it from older specimens from the genus Australopithecus.

Evidence of Australopithecus afarensis disappears at 3.0 million years ago and, with this Homo jaw at 2.8 million years, leaves a gap of only 200,000 years between the two—an important span of time for scientists to continue to explore.

Image credit John Rowan.