Re: Junk DNA and our evolution

Many scientists believe that the "junk" DNA is there for a purpose; we as yet, do not understand the function of these noncoding, often repetitive stretches of DNA in the human genome. It has been suggested that this DNA may serve some structural function in the genome or serve as "spacer" regions between genes. It has also been suggested that some of this junk DNA contains repetitive DNA sequences that may have come from viruses or other types of mobile DNA that have lost their ability to move around the genome. It is also possible that junk DNA has absolutely no function, but since there is little evolutionary pressure to shed these sequences, they have not yet been lost from the human genome.

Since there is no gene coding function for junk DNA, mutations in these regions of the genome seem to have little consequence and thus, there is little selective pressure against these mutations and they can be passed on to subsequent generations. One could make the arguement, as you suggest, that the function of this junk DNA is to be a "target" for mutations.Mutations occur more or less at random in the genome. Since there is little consequence to mutating a noncoding, nonstructural component of the genome, these mutations would be unlikely to affect the viability of the individual and it would be an effetive strategy to protect the essential genes and DNA sequences.