The role of Junk DNA
  Many efforts have been done in order to explain the role of junk DNA, but its function remain to be elucidated. In addition the GC-content variations among species still represent an enigma. Both these two misteries can have a common explanation: we hypothesize that the role of junk DNA is to preserve the mutations probability that is intrinsically reduced in GC-poorest genomes. 
Valentina Agoni
q-bio.OT