Homo habilis
Classification

There is still no wide consensus as to whether or not H. habilis is ancestral to H. ergaster / H. erectus or is an offshoot of the human line, and whether or not all specimens assigned to H. habilis are correctly assigned or the species is an assemblage of different Australopithecus and Homo species. Nonetheless, H. habilis and H. rudolfensis generally are recognised members of the genus at the base of the family tree, with arguments for synonymisation or removal from the genus not widely adopted.

Though it is now largely agreed upon that Homo evolved from Australopithecus, the timing and placement of this split has been much debated, with many Australopithecus species having been proposed as the ancestor. The discovery of LD 350-1, the oldest Homo specimen, dating to 2.8 mya, in the Afar Region of Ethiopia may indicate that the genus evolved from A. afarensis around this time. This specimen was initially classified as Homo sp., though subsequent studies have suggested that it also shares characteristics with Australopithecus and that it is clearly distinct from H. habilis. The oldest H. habilis specimen, A.L. 666-1, dates to 2.3 mya, but is anatomically more derived (has less ancestral, or basal, traits) than the younger OH 7, suggesting derived and basal morphs lived concurrently, and that the H. habilis lineage began before 2.3 mya. Based on 2.1-million-year-old stone tools from Shangchen, China, H. habilis or an ancestral species may have dispersed across Asia. The youngest H. habilis specimen, OH 13, dates to about 1.65 mya.
keywords:frequency