Say it with me: "Cumulative Evolution."
One of the most common objections you see around against evolution is the idea that “this couldn’t have evolved by chance!” It has been rebutted so often and in so many different mediums (journals, books, blogs, videos, etc.) that one would think that it need not be restated. However this flagrant misunderstanding is repeated on a daily basis by Creatards and IDiots. I didn’t realise that it was such a difficult concept to grasp!
Cumulative evolution doesn’t just apply to irreducible complexity style misunderstanding, but also to the borderline brain-dead objection you get from only the most uneducated imbeciles: “things only reproduce after their own kind”. Of course an offspring is related to its parents, no one is saying otherwise. In fact if an offspring was an entirely different species (ignoring hybrids) to its parents, evolution would be falsified! However, an offspring is not identical to either of its parents, and frequently contains genetic mutations — which are often silent (no change in phenotype) — that were not present in either of the parents. Mutation along with recombination, and selection pressures, or simply genetic drift leads to diversified populations over many generations. The absolute failure to grasp the implications of these mechanisms —possibly due to wilful ignorance or dishonesty — results in these idiotic objections being taken as something with credibility.
Analogies are often given to try and explain this basic principle of accumulation of mutations and my favourite one has always been the construction of a building. Obviously a building of any kind is too complex to just arrive in one single step in its final form. This is not how buildings are made though; they are built by a step by step process, one piece at a time. This is comparable to the evolution of a species; it does not differentiate itself from its ancestor species in a single step evolutionary event. The change is slow and cumulative, one or a small number of mutation(s) per generation. Evolution is not monkeys giving birth to humans. Evolution is not cats appearing randomly out of nowhere. Evolution is cumulative change. Period. Creationists would be doing themselves a favour if they decided to understand the subject that they claim to not believe in.