No. 114: Nov-Dec 1997
In principle, the combination of random mutation and natural selection can account for any level of biological complexity you wish to have explained. R. Dawkins' Mount Improbable is never too high to scale with this Darwinistic mechanism -- if given enough time, of course. At times though, we have to wonder if there is not a cog railway or something similar to aid organisms as they ascend this Mount. Such thoughts arose when reading C. Koch's Nature article on neurons and their networks.
Neurons are cells with three principal components: the cell body, the axons, and the dendrites. These cells and the networks underlie all of our perceptions, actions, and memories. The ways in which they store and process information has turned out to be much more complex and dynamic than previously supposed. Neural networks are so intricate that Koch was impelled to conclude his review of current research with this paragraph:
"As always, we are left with a feeling of awe for the amazing complexity found in nature. Loops within loops across many temporal and spatial scales. And one has the distinct feeling that we have not yet revealed every layer of the onion. Computation can also be implemented biochemically -- raising the fascinating possibility that the elaborate regulatory network of proteins, second messengers and other signalling molecules in the neuron carry out specific computations not only at the cellular but also at the molecular level."
(Koch, Christof; "Computation and the Single Neuron," Nature, 385:207, 1997.)
Comment. Thus, Dawkins' Mount Improbable is seen to be even higher and more majestic. Can it really be climbed via a random process edited by natural selection? Even if the answer is "yes," we must ask why atoms and molecules have just those properties that permit them to unite in the marvelously complex and sophisticated biological computers described by Koch.