The evolution of the horse is probably the most famous support of the gradual change of species over time. It is found in textbooks and science museums around the world.

O. C. Marsh worked out the lineage of the horse in the late 1800s.ⁱ It is a chain of creatures from small to large. These creatures, however, all lived at the same time, and there is no evidence linking them together. Variation in size is not an indicator of evolution. Even today there are large variations in the size of horses, but the largest to the smallest all belong to the same species.

The smaller animals in the lineage such as the Eohippus had more toes than the modern horse, or Equus. As well, the species in the lineage vary in the number of ribs they have, from 15 to 19, and the number of lumbar vertebrae they have, from six to eight. These variations would have required genetic reversals. This contradicts the theory of evolution, which states that evolution cannot be reversed.

Marsh’s lineage of the horse is purely speculation, and paleontologists are coming to realize that. In fact, most scientists have completely disowned the diagram of the evolution of the horse. George G. Simpson, a leading evolutionist in the mid 1900s, did not accept Marsh’s lineage. He said, “The most famous of all equid trends, ‘gradual reduction of the side toes,’ is flatly fictitious.”ⁱⁱ

Despite the "fictitious" nature of these claims, we still see them in every school textbook. If scientists have discredited Marsh’s diagram and theory, why are we still teaching it as fact in our schools?

Read about the Cambrian Explosion and evolutionary lawns. Updated June 2009.

i O. C. Marsh, American Journal of Science (1879).

ii George Gaylord Simpson, The major features of evolution (New York and London: Columbia University Press, 1953): 263.