Our fossil records suggest that there once was a group of hominin species. And that the evolution of this hominin group was more like a bushy tree, not a ladder-like progression from ape to human.
Photos of A afarensis and A africanus
However, there is an overall consensus of opinion that H.sapien lineage has passed through ardipithecine to australopithecine, and on to the transitional hominins, pre-modern and finally modern Homo. But exactly which hominins comprise the direct lineage to Homo, has been the 'holy grail'.
The Ontogeny - Phylogeny Calcaneal Model
The OPCM provides a concise and straight forward roadmap in deciphering the Hominin lineage:
Defining the Ontogeny - Phylogeny Calcaneal Model and its' application
Professor/Dr Brian A Rothbart
Director of Research,International Academy RPT