Genome 8th Entry: Self-Interest

Ridley describes in this chapter that how some genes, even through evolution, cause more harm than benefit.  An example would be reverse transcriptase.  It serves basically no purpose in the genome, rather, virus, such as the HIV(which is harmful to the human body) need it to function.  Reverse transcriptase exists in the human body because retroviruses placed themselves there and to survive, they reproduce.  Like reverse transcriptase, many junk DNA in the human genome, only consider about themselves, functioning on behalf of their own benefit, instead of the human's.  35% of the human genome is consist of junk genes.  Ridley believes that from this aspect, revolution is not only about the competition between species, but also a competition between genes that organisms use as their hosts.  However, even if we use more energy to duplicate these junk genes, junk DNA help create an unique set of DNA in DNA fingerprinting.