1. Carl Zimmer in his book Parasites Rex writes about what appear to be extraordinarily complex life cycles of parasites. For example, a parasite might enter a person's heel, tunnel to the blood system, circulate a few times before lodging on specific parts of the liver and then and only then grow 20 feet long. I don't know (or much care) about the specific details except to say that the key to such behaviour is (1) a single program of genetic instructions in the form of "if A then squirm, then if B, swim like hell, then if C, stop swimming etc."
In other words, we have a finite set of instructions where the parasite is COMPELLED to react in a specific way to specific stimuli.
2. (1) is very interesting from a risk management point of view. Why? Because where the parasite goes from one species to another in its life cycle, it is merely following a PATH that has been established for many thousands if not millions of generations. In other words, the parasite's apparent complex behaviour actually is quite STABLE in reflection of the environment in which it lives. Thus, the instruction, "When human foot enters the pond sending a chemical signal, parasite will swim like crazy and burrow into the human's heel" could only have become a recipe of survival if lots of humans pass through such shallow waters, and human bodies have very similar circulatory systems down to the molecular chemical taste and smell levels. And, not only do we have a stable single strand set of instructions in the parasite, but we also have apparently (2) RISK PERVERSE behaviours exhibited by the "survival machines carriers" which make up most of the life cycle environment of the parasite. How risk perverse? Well, if a snail say is infected by "mind controlling" parasites (see "Zoombies snails" on YouTube) the snail's behaviour is RISK SEEKING. You'll see the same risk perverse behaviours in other animals infected by parasites, e.g. fish swimming to the surface waters SO IT CAN BE MORE EASILY EATEN by the passing pelican and so on.
3. Let's generalise a bit. If a SET OF INSTRUCTIONS is isomorphic to the ENVIRONMENT OVER TIME, from which the ENTIRE ECOLOGICAL SYSTEM has a lower probability of collapse then each of the LINKS or CROSS-SPECIES INTERACTIONS must each produce a lowering of entropy to the entire system of exchanges. OK, if not a lowering of entropy because in general entropy never decreases in the universe, then there is a LOWERING OF UNCERTAINTY per interaction. Thus, information and communication stability is greatly increased by parasites! At one level, the effect of a parasite on an ecology therefore is to "stitch it together" by reducing the survival strength of an infected individual. At another level of abstraction, the ROTATIONAL or RING SYMMETRY of the parasite's life cycle literally ENABLES an ecological system to continue to exist.
4. Now can these ideas be applied to different phenomena? I suppose yes. It's in making comparisons to other phenomena that Category Theory may help since one of the basic motivations of Category Theory is to ensure that when we do compare two objects, whatever structure we find for the entire system of comparisons holds for each and every object and the morphisms between them. As a fun mental gymnastic, you might think: (1) how the government to bond market interaction is parasitical with (a) the government as parasite or (b) hedge fund as parasite. There are different intensities for the host-parasite relations--from mutual beneficial to commensual to totally mutually destructive. My own view is that someone who is very adept at law and finance and is called a "parasite" should feel chuffed at the inadvertant laudation. The adept parasite, after all, is simply executing excellently on a set rules that fit very well to very real situations. And oh by the way, you can always distinguish someone who has been infected--they wear suits and ties and shinny shoes.
