The genus is estimated to be about 2.3 to 2.4 million years old,  evolving from australopithecine ancestors with the appearance of Homo habilis.. 
Àwọn olùdásílẹ̀ rẹ̀ ni Henry Clay, John Randolph, àti Richard Bland Lee.Ìtọ́kasíìtàn àwọn ọmọ Áfríkà Amẹ́ríkàìtàn ilẹ̀ Làìbéríà.. 