Beep. Circle takes the square. The theory is called "evolution." Survival of the fittest is only part of one possible mechanism by which organisms change over time. Since you have yet to understand even this simple concept any discussions with you will probably be fruitless.
Yup, for every argument, there is a different lie made up by evolutionists. If there are similar features in two species, then that is evolution. However, if the features could not have descended from each other, then that is evolution too. If it is gradual change it is evolution. If it is sudden change, it is evolution. There are always two sides to every story and whatever side it is it is evolution. That is why evolutionists will never state the theory of evolution, they will never say how evolution happens. They always leave the question open so that they can make up some ad hoc nonsense to cover their behinds.