"Junk" DNA as a genetic decoy

We propose that the evolutionary purpose of junk DNA is to protect the gene. Mutation agents, such as retro-viruses, hit ``decoy'' DNA most of the time. Although the argument is far from general, we propose that the percentage of junk DNA should correlate with the number of retroviruses attacking a given species. It should also anti-correlate with the ideal mutation rates (higher in insects than in mammals).