See text for extinct species.
Homo is the genus that includes modern humans and their close relatives. The genus is estimated to be about 2.5 million years old, evolving from Australopithecine ancestors with the appearance of Homo habilis. Appearance of Homo coincides with the first evidence of stone tools (the Oldowan industry), and thus by definition with the beginning of the Lower Paleolithic.
All species except Homo sapiens (modern humans) are extinct. Homo neanderthalensis, traditionally considered the last surviving relative, died out 24,000 years ago, while a recent discovery suggests that another species, Homo floresiensis, may have lived as recently as 12,000 years ago. Given the large number of morphological similarities exhibited, Homo is closely related to several extinct hominin genera, most notably Kenyanthropus, Paranthropus and Australopithecus. As of 2007[update], no taxon is universally accepted as the origin of the radiation of Homo.