The information capacity of the genetic code: Is the natural code optimal?

Area of Science:

• Molecular Biology
• Information Theory
• Genetics

Background:

• Molecular evolution involves changes in genetic material over time.
• Understanding information preservation is key to deciphering evolutionary processes.
• Shannon's channel coding theorem provides a framework for quantifying information transfer.

Purpose of the Study:

• To quantitatively measure information preservation in molecular evolution.
• To assess the information capacity of DNA at nucleotide and amino acid levels.
• To evaluate the optimality of the natural codon-amino acid code and explore evolutionary scenarios.

Main Methods:

• Applying Shannon's channel coding theorem to molecular evolution.
• Calculating information capacities of DNA using nucleotide and amino acid substitution models.
• Employing an adaptive search algorithm to explore the genetic code domain.

Main Results:

• Information capacities were calculated for DNA at both nucleotide and amino acid levels.
• The natural codon-amino acid code's optimality was discussed in relation to information capacity.
• A large number of genetic codes with higher information capacity were identified.

Conclusions:

• The study supports the hypothesis of an ancient evolutionary extension from 2-nucleotide to 3-nucleotide codons.
• The findings provide a quantitative information-theoretic perspective on molecular evolution and genetic code structure.