In complex environments, there are costs to both ignorance and perception. An organism needs to track fitness-relevant information about its world, but the more information it tracks, the more resources it must devote to memory and processing. Rate-distortion theory shows that, when errors are allowed, remarkably efficient internal representations can be found by biologically-plausible hill-climbing mechanisms. We identify two regimes: a high-fidelity regime where perceptual costs scale logarithmically with environmental complexity, and a low-fidelity regime where perceptual costs are, remarkably, independent of the environment. When environmental complexity is rising, Darwinian evolution should drive organisms to the threshold between the high- and low-fidelity regimes. Organisms that code efficiently will find themselves able to make, just barely, the most subtle distinctions in their environment.
The evolution of lossy compression
Sarah E. Marzen, Simon DeDeo