Photoreceptors operate at the outermost boundary allowed by the laws of physics, which means they are as good as they can be, period. Each one is designed to detect and respond to single photons of light — the smallest possible packages in which light comes wrapped. …
Photoreceptors exemplify the principle of optimization, an idea, gaining ever wider traction among researchers, that certain key features of the natural world have been honed by evolution to the highest possible peaks of performance, the legal limits of what Newton, Maxwell, Pauli, Planck et Albert will allow.
So all those sloppy, repetitive, inefficient, evil designs revealed and proved evolution because, after all, evolution has no guiding light but can only work with whatever random mutations will give it. But when optimized designs are found, evolution suddenly becomes the brilliant physicist, honing master designs.
There are many more such examples of optimized designs, such as how bacteria optimize their search for food, how fruit fly embryos use the concentration of a particular protein, and how sharks detect tiny voltages in the water:
Scientists have identified and mathematically anatomized an array of cases where optimization has left its fastidious mark, among them the superb efficiency with which bacterial cells will close in on a food source; the precision response in a fruit fly embryo to contouring molecules that help distinguish tail from head; and the way a shark can find its prey by measuring micro-fluxes of electricity in the water a tremulous millionth of a volt strong — which, as Douglas Fields observed in Scientific American, is like detecting an electrical field generated by a standard AA battery “with one pole dipped in the Long Island Sound and the other pole in waters of Jacksonville, Fla.” In each instance, biophysicists have calculated, the system couldn’t get faster, more sensitive or more efficient without first relocating to an alternate universe with alternate physical constants.
As usual, all this is a surprise to evolutionists:
On Wednesday, Dr. Bialek will discuss his take on biological optimization at the Graduate Center of the City University of New York, in a public lecture fetchingly titled “More Perfect Than We Imagined: A Physicist’s View of Life.”
Muscles provide more examples of optimization:
Dr. Todorov has studied how we use our muscles, and here, too, he finds evidence of optimization at play.
And the brain:
The brain, too, seems built to tolerate bloopers and static hiss. Simon Laughlin of Cambridge University has proposed that the brain’s wiring system has been maximally miniaturized, condensed for the sake of speed to the physical edge of signal fidelity.
Aside from the problem of how random mutations are supposed to have accomplished such wonders, and aside from the obvious just-so story that “evolution did it again,” there is the other problem such fine-tuning of designs may well be beyond the resolution of selection. Can we really believe that the ability to detect a single photon provided an important advantage over a higher threshold, such as two photons, or ten, or 20?
The answer, of course, is “of course.” After all, that’s the design, and it must have evolved.