Darwinists believe that evolution advances primarily via natural selection acting on genetic mutations. The more genetic variation there is, the more room there is for evolutionary advancement. Evidence against the neo-Darwinian synthesis is mounting every day. It is simply not borne out by the data. Here is another case in point.
Alfie Clamp is a two year old boy who has been diagnosed with having an extra strand of DNA on chromosome seven. Did this additional genetic information help Alfie in the struggle for survival? No. It caused him to be born blind, he has to take a cocktail of drugs every day so his body will absorb nutrients from his food, and he has stopped breathing multiple times. It seems as though regular mutations are too few and too slow to produce novel biological change, and large novel mutations are detrimental to an organism. Either way, evolution will not proceed.