The postulated mechanism of evolution consists of two components:
Mutation – “A sudden departure from the parent type, as when an individual differs from its parents in one or more heritable characteristics, caused by a change in a gene or a chromosome.” (The Random House Dictionary)
Almost all mutations are acknowledged to be harmful, but evolutionists posit that a few are beneficial and provide the new material (the new information) for natural selection to operate on.
Natural Selection – the idea that nature preserves traits (variations introduced by mutation) which result in a reproductive advantage (traits that cause an individual to leave more offspring). Commonly referred to as “survival of the fittest”. Natural selection is not a creative process, it only selects among existing alternatives.
Even though evolutionists posit that mutations can introduce new information, there is not a single documented mutation shown to increase genetic information. In fact, mutations disturb and degrade the existing information, just as changing letters at random in a book will degrade the quality and readability of the book. So-called beneficial mutations, like the loss of wings by birds on isolated islands, allowing them to dive and swim better, represent a loss of information (the information needed for wings in this case).