Why the Immune System Is So Damn Complicated
6th April 2014
So where does all this Rube Goldberg action come from? It’s tempting to blame evolution, and the accumulation of cruft in the genome, but evolution can be quite good at simplifying when simplicity is actually optimal. We have only one backbone in our body, not five sort-of-parallel ones all trying to combine to support us. So there must be something optimal here about complexity, and when considered it’s obvious: if we could understand the immune system easily, so could microbes, and so they could subvert it easily. Indeed, it seems like whenever I read about the workings of any well-studied human pathogen, those workings include at least one way of eluding, deceiving, or sabotaging the immune system, and often two or three of them. Germs don’t seem to qualify as human pathogens, in the eyes of doctors, unless they have such a way; otherwise they are just one of the “harmless” background microbes which the immune system usually deals with so efficiently that we don’t even know that they are trying to eat us (though they can still be harmful in high doses). Yet even when a germ has three different ways of eluding the immune system, that doesn’t make it 100% deadly; most of the time the immune system can still eventually get it under control, using a fourth (and maybe a fifth and a sixth) mechanism in its arsenal.
April 10th, 2014 at 11:30
“So where does all this Rube Goldberg action come from? It’s tempting to blame evolution, and the accumulation of cruft in the genome, but evolution can be quite good at simplifying when simplicity is actually optimal. We have only one backbone in our body, not five sort-of-parallel ones all trying to combine to support us. So there must be something optimal here about complexity, and when considered it’s obvious: if we could understand the immune system easily, so could microbes, and so they could subvert it easily.”
Random chance, time and energy acting on matter does not design a “complex” system of defense. In fact, these working in concert are the ubiquitous destructive influence on everything, including the genome where the coding for the immune system is found. The second Law of Thermodynamic is no respecter of ANY matter.
Geneticists have in fact stopped looking for or labeling anything in the genome “cruft”. That has happened so many times in the past only to delay understanding of what the true function was of the “cruft”. If we are the product of random chance and time there would be sections of “cruft” randomly plugged into the genome. But they just aren’t finding it.
To add to this complex system, it is fascinating to know that the protein that signals pregnancy in mammals (maybe other species but I have no experience other than mammals) is an interferon molecule. Interferons are a family of molecules that acts on and within the immune system. Isn’t that convenient? An immune system modulator tells the female’s body that it is pregnant and switches off the attack the would otherwise ensue on a “foreign” invader. The tissue markers for the baby would be foreign to the mother and without intervention the mother’s immune system would attack the baby because the baby is a distinctly separate individual.
Huh, sounds like design to me. I personally am impressed with the Designer.