Gradualism

The gradualism is a concept of the theory of evolution. He has two different meanings. In the context of evolutionary gradualism rate means that the rate of evolution is constant ( phyletic gradualism ). In the context of the evolution of adaptations gradualism means that adaptations are formed through many intermediate steps and do not appear suddenly.

The phyletic gradualism occurs when the rate of evolution is constant. If the rate of evolution within a species slower than the formation of new species, it is called instead of punctuated equilibrium. While the Darwinian theory of evolution is not dependent on the phyletic gradualism, gradualism is without alternative component related to the evolution of adaptations.

Darwin always stressed that the evolution is slow and gradual. Stephen Jay Gould concluded that the phyletic gradualism Darwin so that meant, and that the theory of punctuated equilibrium Darwinism and neo-Darwinism thus contradicting. Richard Dawkins, however, noticed that Darwin was not referring to the rate of evolution and speciation. Darwin's observations in the latter context are quite compatible with the punctuated equilibrium:

" Many species learn when they are formed, never more changes (...) and the periods during which the types of modification have been unsuccessful, were as measured by years long, but probably in relation to those in which they remained unchanged are, but only briefly. "

Darwin and all subsequent versions of Darwinism were gradualist in relation to the evolution of adaptations, but not in terms of the rate of evolution. The only condition which presents the evolution of the rate of evolution is that fossils are not allowed to evolve faster than the fastest experimentally proven and based on normal genetic variation evolutionary rates. Should this condition not be met, this would be a serious challenge to neo-Darwinism. However, all are slower than those from genetic experiments to date known fossil evolutionary rates.