Inventor and Designer of Postural Control Insoles
Tracing the Human Lineage
The Ontogeny - Phylogeny Calcaneal Model
This OPCM is based on my clinical research which entailed the discovery of a previously unrecognized inherited foot structure, the PreClinical Clubfoot Deformity (Structure). The hallmark of this foot structure is the structural twist (supinatus) in the posterior aspect of the calcaneus. This is the same structural twist found in the fossilized calcaneus of the H.naledi but lacking in the A.africanus. From this the OPCM would conclude that H.naledi is a direct descendant of H.sapien, A.africanus is not.
The PreClinical Foot Structure appears to be at least 2 million years ago and possibly older.
The most common foot structure in our population today is the PreClinical Clubfoot Structure/Deformity.
The least common is the Plantargrade Foot Structure (heel bone no longer retains any supinatus/structural twist).
I opine that the homo sapien foot is still very early in its anthropological evolution, evolving from the bipedal dysfunctional PreClinical Clubfoot structure towards the very stable bipedal plantargrade foot structure.
It has become progressively apparent that the H.sapien has emerged from a rather bushy phylogeny, where there once was a diverse and divergent group of hominin species.
Teasing out the precise relatedness of these hominin fossils to one another has proved to be a daunting enterprise. The sheer diversity of the fossilized remains has complicated our understanding of H.sapien's evolution.
For example, it appears that A.ramidus was a direct descendent of H.sapiens. However determining whether A. afarensis or A. africanus (both habilitating the earth during the same epoch) were direct descendants or not, has proved more difficult to determine.
Photo of the foot fossil of H.naledi
Courtesy of Berger LR et al 2015. Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa. DOI: 10.7554/eLife.09560
There is an overall consensus of opinion that H.sapien lineage has passed through Ardipithecus to australopithecine, and on to the transitional hominins, pre-modern and finally modern Homo. But exactly which hominins comprise this direct lineage to Homo, has been the holy grail.
The Ontogeny - Phylogeny Calcaneal Model (OPCM) (as proposed by Dr. Rothbart)
The OPCM provides a concise and straight forward roadmap in deciphering the Hominin lineage.
Calcaneal supinatus (twist pattern in the posterior aspect of the heel bone) is the marker in determining whether or not the fossilized heel bone comes from a direct descendant of h.sapiens, or not. The calcaneus in both the H. Naledi (Recently discovered - See Photos below of structurally inverted calcaneus and full face of H Naledi) and A. afarensis have calcaneal supinatus. A. africanus lacks this twist in the heel bone.