[uncbob]

Once again it was a sudden dorso-ventral transformation of the modules of the body axis--a remarkable reorganization of the vertebral column in which some parts moved forward and others shifted backward--that generated an upright species.

And what was the mechanism that caused this

[ml/nj]

And what was the mechanism that caused this

A vivid imagination.

ML/NJ

[MrB]

Ancient chiropractors.