The Immune System as Anti-Optimizer
We have a short list of systems we like to call “optimizers” — the market, natural selection, human design, superintelligence. I think we ought to hold the immune system in comparable regard; I’m essentially ignorant of immunobiology beyond a few YouTube videos (perhaps a really fantastic LW sequence exists of which I am unaware), but here’s why I am thinking this.
The immune system is the archetypal anti-optimizer: it defends a big multicellular organism from rapidly evolving microbiota. The key asymmetry:
- Specified once by the genome. It cannot rewrite its own source code between generations. Its adversaries evolve orders of magnitude faster.
- Resource asymmetry as counterbalance. Whole organs are devoted to the adaptive immune response. A microbe is one cell; the immune system is a civilization.
- This extends to cancer. The immune system typically out-adapts malignant cells despite selection acting far more rapidly on them. Immunosurveillance fails not because it is weak but because cancers occasionally evolve to exploit its specific tolerance mechanisms.
In short: the immune system embodies enough amortized optimization power to defend against online adversarial attacks by natural selection, because these attacks are constrained by the comparative simplicity of the attackers. One optimizer constrains another, faster and more adaptive optimizer, by having more resources.
What makes this especially interesting is that the immune system has no discernible volition. It is complex — probably far more so than I appreciate — but intuitively much more like a thermostat than a scheming eldritch god. It optimizes powerfully, within bounds that feel legible and non-agential.
I will not be so crass as to say “big if true for alignment”, but you are permitted to infer this if it please you. I just think it’s neat. Consider the mere phrase “semiotic immune system” (from, if I recall correctly, Charles Stross’s Accelerando) — suggests a lot at once, eh?
I asked Claude to prepare the following tutorial - which I have not yet read (longa est vita, si uti bene scias) - developing this theme: Immunology and Optimization: A Tutorial
Revised with Claude.