  The present paper is devoted to foundations of p-adic modelling in genomics.
Considering nucleotides, codons, DNA and RNA sequences, amino acids, and
proteins as information systems, we have formulated the corresponding p-adic
formalisms for their investigations. Each of these systems has its
characteristic prime number used for construction of the related information
space. Relevance of this approach is illustrated by some examples. In
particular, it is shown that degeneration of the genetic code is a p-adic
phenomenon. We have also put forward a hypothesis on evolution of the genetic
code assuming that primitive code was based on single nucleotides and
chronologically first four amino acids. This formalism of p-adic genomic
information systems can be implemented in computer programs and applied to
various concrete cases.
