Charles Darwin hit upon on his grand theory of evolution after observing physical changes in finches on the Galapagos Islands. He was witnessing what is now known as natural selection, adaptive changes within a species. Each species’ genetic code allows for adaptations to changes in an organism’s environment (What an awesome Designer we have!).
 
The problem with Darwin’s theory is that DNA isn’t able to add genetic information to itself. In fact natural selection typically results in a loss of information – but nothing new. Not ones to let facts get in the way of their presuppositions, Neo-Darwinians decided that evolution must somehow occur due to mutations. Well that idea’s not panning out either because the accumulation of mutations always decreases fitness. This process, is called “genetic entropy.” – Genetic Entropy Confirmed.

This post at Creation/Evolution Headlines is fairly heavy in technical jargon but even I, scientifically challenged as I am, can get the gist of it:

Most mutations are nearly neutral and invisible to natural selection, as Sanford (a geneticist at Cornell) explained in detail in his book. Because they are not eliminated by purifying selection, they therefore accumulate in the genome, dragging it into genetic entropy. Mutations are not good material for natural selection.