Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Hierarchical evolution of the Analog Information System (AIS) in the early stage of peptide/RNA world. The most basic AIS is termed ‘Molecular Preference AIS’. The higher-level stage AIS is built upon the lower-level AIS. For example, the next stage of AIS, the wet–dry AIS, subsumes the molecular preference AIS, and so on.
