The controversy surrounding the nucleic acids and proteins, regarding which one of them was formed first is the most popular controversy in the biology world today. The nucleic acids stores and the genetic information. The proteins essential for all the life processes are encoded by the genes formed of the nucleic acids (DNA and RNA). But proteins (enzymes) are required for the formation of proteins from the genes. The inter-dependency of the nucleic acids and proteins on each other possesses a dilemma to the question 'which of them arrived first'.
The answer to this dilemma was answered when it was discovered that RNA was capable of not only carrying the genetic information, but also acting as catalyst to the chemical reaction. This finding supported the notion that the RNA evolved first serving the purpose of both the nucleic acids and emzymes.
Different forms of a given gene are known as "alleles". Alleles are essential for the formation of life and add to diversity both within and outside the organism itself in many ways.