Write a 16 pages paper on the evolution of the horse. The evolution of the modern-day horse is thought to have begun an estimated over 58 million years ago. In a description of some newly discovered horse fossils published by paleontologist O.C Marsh in 1870. MacFadden (2005b) points out that Marsh described an evolution that took place in a single lineage. In this description, through a series of distinct intermediates, the Eohippus fossil species gradually evolved into what is an almost totally different-looking descendent, the Equus. The American Museum of Natural History further popularized this description by assembling a famous exhibit of these fossil horses. In designing the exhibition, the remains were arranged in such a manner that they would show the gradual evolution from Eohippus (Hyracotherium) to the modern-day Equus. Exhibitions such as these were seen to not focus on the evidence of evolution, but on the evolution of the modern-day Equus as a model of gradual and straight-line evolution. This model was soon to eventually be included in all the biology textbooks.
Recent evidence has however clearly shown that the very first horse evolution did not proceed in a straight line as had earlier been supposed. Fossil evidence now shows that the familiar Equus is merely one evolutionary branch of the equine species and that we only have the illusion of a straight-line evolution because Equus is the only branch of the equine species that survived. New fossil evidence also shows that the evolution of the horse was not always smooth and gradual. A number of different traits did not always evolve together and when they did, they evolved at different speeds. Some of these traits also experienced the occasionally reversed direction evolution. In addition to this, horse species did not always evolve through a process of the gradual transformation of their ancestors (anagenesis). .