Richard Dawkins, and later Doolittle, Sapienza, Orgel, and Crick, developed the Selfish Gene theory, according to which the true purpose of DNA is to survive, and the best way it has found is through the use of vehicles: animals. This theory therefore explains the large percentage of genes (junk DNA) that are not used to synthesize proteins and therefore have no phenotypic expression but are simply parasitic DNA that propagates itself through the generations.
