Probably much more important is that natural selection makes evolution highly non-random. A favorable mutation has greatly increased probability of becoming established; a detrimental one has a greatly decreased chance of becoming established. The pattern of mutation does appear random in some senses of the word, but superimposed on that is the directional component of selection. If anyone wants more details, any population genetics text will give formulas.
The illustration of the puzzled codebreaker does illustrate another aspect overlooked in the quotes disparaging the effectiveness of random processes. Lots of random arrangements will give coherent sentences; many more will give comprehensible approximations of sentences. The codebreaker by providing the selective pressure of a search for a military meaning eliminates numerous unsuccessful interpretations of the message. As long as the codebreaker picks an interpretation that pleases his superior officer, even if it is not exactly the message sent, he will keep his job. Likewise, there are generally numerous ways to get a protein to do a particular job.
Dr. David Campbell
"Old Seashells"
NEW ADDRESS AS OF 8/21/00
Biology Department
Saint Mary's College of Maryland
18952 E. Fisher Road
St. Mary's City, MD 20686-3001 USA
dcampbell@osprey.smcm.edu, 301 862-0372 Fax: 301 862-0996
"He had discovered an unknown bivalve, forming a new genus"-E. A. Poe, The Gold Bug
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