Replicable Codes and Steady-State Excitations
Concerning a physical perspective on some key elements of life:
We are steady-state excitations, while many of the things that we serve, protect, and hold sacred are replicable codes. For example, heat-engines (like gas-powered motors and photosynthetic plants) and information engines (like copy machines and ourselves) are steady-state excitations, while genes (like the DNA that holds your genetic heritage) and memes (like your favorite songs, fashions, beliefs, laws, and ideas) are replicable codes.
This distinction between replicable codes and steady-state excitations perhaps first became useful not with our discovery of the DNA base-pair code (1950's), nor with the beginnings of information theory (late 40's), nor for that matter with Plato's formal recognition of ideas as separate entities (BC). Instead, following recent comments by Lynn Margulis for Scientific American, I suspect that this distinction became useful much earlier, with the invention in practice of genetic bargains in cell reproduction. As Lynn points out, the distinction between excitations and codes became a hard reality with the pre-vertebrate invention of programmed-death for multicelled organisms, since before this one just split in two to create one's offspring! After death, only the code's chance at immortality survived.
In the early days of replicable ideas, memes (rhymes with "beams") bypassed the fate of the excitations carrying them as well, but only by leaping from one individual to another almost like a virus. The idea of fire-building is a likely example in this regard. The reproductive power of these memetic replicators has since taken quantum leaps, with the invention(s) of dance, music, language, song, theatre, writing, the phonetic alphabet, printing presses, electronic media, and now the world wide web.
In matters of evolution:
Among multi-celled lifeforms on earth, it is the codes or replicators, and not the excitations that literally evolve with time, even though both codes & organsims are key physical components of the phenomenon we call life. Likewise, even life's competition is between codes perhaps as much or more than it is between organisms! Early evolutionary thinking, as one might expect, was relatively "organism-centric" in this regard, as have been most "hard-science" perspectives on life. Perhaps they had better not be any longer. Ideas as distinct from excitations not only live, and evolve, and deserve recognition. They also deserve respect and caution since, from the vantage point of a code, humans and computers as information engines alike could be little more than disposable vehicles for survival (to paraphrase Dawkins' in The Selfish Gene). As we have I hope already learned by mistake, ideas can be powerful and ignore our humanity just the same.
Information physics on the web.