Final answer:
Some of the oldest evidence for early hominins date back to nearly seven million years ago, notably with the species Sahelanthropus tchadensis. Subsequent discoveries include Ardipithecus, dating back to about 4.4 to 5.6 million years ago, and even earlier members of the genus Homo, such as Homo gautengensis, which may predate H. habilis dating between 2.5 to 3 million years ago.
Step-by-step explanation:
The evidence for some of the very early hominin-like ancestors is quite ancient, with some fossils dating back nearly seven million years. One of the oldest discoveries is that of Sahelanthropus tchadensis, a species uncovered in 2001-2002, which has been dated to nearly seven million years ago. Its fossil, nicknamed "Toumai," shows a mixture of primitive and evolved characteristics. Another early hominin, Ardipithecus, which dates back to around 4.4 to 5.6 million years ago, includes two species: A. ramidus and A. kadabba. Evidence of bipedality has been found in these species.
As the hominid lineage developed, the genus Homo emerged between 2.5 and three million years ago. The discovery of Homo gautengensis in 2010, which may predate H. habilis, pushes the origins of the genus Homo even further back. In terms of later evolution, fossils of Homo antecessor found in Europe are dated to around 1.2 MYA to 800 KYA, representing some of the oldest evidence of Homo in Europe.
Throughout the late Miocene, between approximately 10 to 5 million years ago, hominids began adapting to life on the ground. This period is marked by sparse fossil evidence, but it signifies the important shift from arboreal to terrestrial living in our ancestors.