Bilbo I am a biological scientist with a background in molecular biology and Botany and i disagree with you. Molecular biology supports the theory of evolution. DNA changes naturally and easily by a number of processes including crossing over and recombination. They are always involved in any sexual reproduction.

It's not only the absence or presence of a gene that dictates a trait but it's level of expression. A little growth hormone = a little growth - a lot = a lot. This can be altered by changing just one base pair in the activation site of a transcription factor. Small changes in DNA can have huge effects.

All you have to see to know that is the difference between parents and their children. Variation is natural. It'd be weird to be the exact clone of your parent because that never happens.

Not all changes to DNA are beneficial of course and I'm sure that the larger nose I have than my mother will not help me pass my genes onto the next generation. thus not all changes in the DNA code are improvements or continue to be inherited but they don't all have to be.

The random part is taken out by a selection pressure which will deem a trait an advantage or disadvantage according to whether or not the gene carrier will have to opportunity to procreate.