This evolution is a type of evolution in which theoretically it is proven that in most cases speciation is slow, uniform, and gradual. When this occurs the result will be seen through the development of new species due to the process of steady transformation of whole species. The word phyletic evolution is given by the American paleontologist G.Simpson, and he distinguishes it from speciation. The word phyletic derives from the Greek which means a line of descent. In this most evolution occurs isolated in rare episodes of rapid evolution. This evolution is characterized by moderate or low evolution rates and is detected when one studies the evolution of supra species taxons.