Storm Raven said:
This would be a wonderful analysis, if digesting food was a learned behaviour or skill. It is not, and you just look silly making this sort of comparison.
Let's say our hypothetical child grows up and turns 30, never taking of his ring, never eating. The last time he had a bowel movement was to pass meconium after birth. Now, he takes off the ring and eats a sandwich. This is difficult, and he bites his tongue a lot and ends up swallowing fairly large pieces, being unaccustomed to manipulating objects in his mouth...but happily swallowing is a reflex and so he chokes it down, despite the way his salivary glands don't function properly because he was never trained to identify food by smell or taste and so they don't respond well to the smell or taste of the sandwich to help moisten and lubricate the food to help it go down.
Having never had any contact with the proteins in the food, his immune system may go into shock as it attempts to deal with substances for which it is largely unprepared to handle. While the simple lipids and sugars in the sandwich are unobtrusive, there are many proteins that the body might identify as pathogens since it has never run across them before. Individually, he might be able to handle them, but as a package it's likely to cause a lot of trouble. There's a good chance he might go into anaphylactic shock.
Then there's the intestine. The intestine is lined with smooth muscle and in a normal person operates almost constantly, pushing digested food through by peristalsis. Toward the end, the bulk becomes tougher, and requires more pushing to move. However, our boy has never used his smooth muscles, and so they're so atrophied that he'll be lucky to push water through that intestine. If he had a ring of flying and never used his legs to walk, stand, or alter his position (and like some people confined to wheelchairs), his leg muscles would be tiny and useless. Likewise with his intestine. That sandwich isn't going anywhere. Even if it makes slow progress, it'll probably start to rot. His intestinal wall will have no "friendly flora" of helpful bacteria, because they will never have had anything to feed on, there being no food passing through for 30 years. The only bacteria present will be from spores present on the sandwich itself, which will likely include many anaerobic bacteria that enjoy the conditions of an uninhabited intestine. The rotting sandwich will give off gas that will cause painful cramps, and if it doesn't get out of there quickly it could cause an infected blockage that will lead to an unpleasant death. Even if it does, an infection could still result.
The body might be able to respond to the problem by flooding the intestine with water in the hope that diahorrea will simply wash the sandwich out of there before it can do any more harm. That might work, and if it does, I don't think our boy will be eating any more sandwiches after that kind of experience.
Aside from wholly automatic processes like the beating of the heart, endocrine responses, sweating, and the like, much of what we do depends on a set of preliminary conditions in which we learn to do the things we do. Babies are born with a suckling reflex. But they need to be taught how to nurse properly or else they could end up not getting enough milk, or only watery foremilk, which can cause gastric problems and low weight. It is much more efficient for the body to have DNA that codes for "learning to deal with something" than "knowing how to do something" if the conditions for learning are guaranteed to be present. The former is less complex to code for than the latter, and learned behaviour is one of the major evolutionary steps that helped mammals dominate the planet. It makes them adaptable and it is more efficient than trying to code for increasingly complex behaviour, which is in many cases likely much too complex to be coded for at all.
If you keep your eyes closed for the first few years of your life, you'll have a hard time learning how to see when you finally do open them. It'll just be a mess of overwhelming visual stimulus in which you have trouble making out objects. Your DNA codes for an ability to learn to process the information that your optical sensory organs pass on to the brain. That you have these organs is completely genetic, but your ability to use them requires stimulus during a critical developmental phase, and after that it becomes much harder to learn. Nature activated by nurture, nurture made possible by nature. A synthesis of a false paradigm of thesis and antithesis.