Evolutionary provocations: Paul Sondaar, the evolution of the horse, and a new look at the origin of species

From the days of the Synthesis on, the evolution of the horse has served as one of the major examples of smoothly transitional evolution. Yet, Simpson, who promoted this scenario, had to acknowledge that this was not documented in the fossil record and, therefore, he was driven to provide an explanation of what he thought happened during the periods represented by gaps. Schindewolf, however, took the evolution of the horse and a plethora of examples from the invertebrate and vertebrate fossil records as evidence of profound organismal reorganisation associated with the origin of species. Schindewolf also backed up his ideas with developmental studies. A new theory of evolution based on regulatory genes and Mendelian inheritance demonstrates that the effects of mutation and inheritance naturally produce new species without a smoothly transitional trail of intermediates. Thus, gaps in the fossil record are real and to be expected.