Information plays several roles in biology. Structures and processes reproduce equal to themselves for hundreds of millions, perhaps billions of years, altered only by the slow drift of evolution. The principal means of this stability are the molecules of DNA, which remain more or less similar to their ancestors. This implies that there are correlations, that is to say relative information, across eons of time. The molecules of DNA codify and transmit information. This informational stability is perhaps the most characteristic aspect of living matter.
