G1 Cybertron didn't 'evolve' from an organic world. The original organic surface was completely supplanted by Primus hence why you have those underground mutant things living in Cybertron's core.

There is no evolution between the original organic inhabitants and Transfomer Cybertronians. There is something else that BM stuffed up as it also implied linear evolution of the origanic world before Cybertron and Primus' reshaping of hat world.