I’ve been off-line for a while, and I know this is old and peripheral, but I couldn’t let this pass. If you’re going to correct someone’s (Phil’s as it happens) scientific concepts, then you should really understand what you are talking about. Almost everything you have said here is either wrong or muddled.
DNA is the molecule that carries the genetic code. A gene is a stretch of DNA that codes for a protein (but also for RNA), A chromosome is the physical embodiment of DNA in a cell, consisting of a very long stretch of DNA containing many genes and non-coding sequences, packaged by histone proteins to form the complex of DNA and protein called chromatin. Alleles are alternative versions of a gene which exist in different members of the same species.
Now it is perfectly acceptable to say that mutations occur at the level of DNA - in fact that is precisely where they occur. A mutation is simply an error in copying the DNA sequence and it can occur during meiosis or mitosis (although only the former is heritable). Your statement about alleles is just muddled.
As for the environment and other factors being redundant, that is not so. Although the environment acts through natural selection, it also acts through epigenetics, the effect of non-coding influences including environmental conditions which affect the timing, location and intensity of protein expression, causing quite radical differences between organisms even though the underlying genetic code might be identical.
Alec
evolutionpages.com/intro_evolution.htm