"The Devil is in the details"
Arthur S. Lodge | home
Evolution: Main Open Questions | Scientific Theories of Evolution | The Neo-Darwinian Theory: Version 2004 | Darwinism: Scientific Theory, Research Program, or Faith? | Crow & Swift: the Neo-Darwinian Theory Range of Applicablity | Bio-logic | The Devil in Neo-Darwinian Theory Details | Industrial Melanism | Mathematics of Evolution | "Unlikely Events" Fallacies: | Scientific Theory Testing | Strong & Weak Falsifiability | Censorship | No Reply | | The Neo-Darwinian Theory Range of Applicability | What is Natural Selection? | Critics' Motivation | Darwinism's Debit Sheet: 23 items | Criticisms of "Finding Darwin's God" | A criticism of "Gene Avatars: The Neo-Darwinian Theory of Evolution" | Andrew Knoll: Life on a Young Planet | Natural Selection | --Type Title Here--
The Devil in Neo-Darwinian Theory Details
How does the NDT account for macroevolutionary changes? Let us consider (for example) the evolution of a bacterium into a daffodil. The following detailed steps in the argument would seem to be necessary.
1. The daffodil genome contains genes not present in the bacterium genome.
2. The change involves a large and unknown number N (probably millions) of small steps.
3. The change took place over a large and unknown number Y of years (probably million).
4. Each step is the result of an unknown random, spontaneous, mutation.
5. Each step has an unknown selective advantage.
6. Our ignorance of the values of N and Y does not matter.
7. Our ignorance of the nature of the mutations in 4. does not matter.
8. Our ignorance of the nature of the selective advantages in 5. does not matter.
It is clear that this type of application involves a large number N of "explanatory blank checks" that have not, and probably never will, be filled in. As stated, this part of the NDT appears to be untestable and unfalsifiable and, therefore, according to some, unscientific.
When I asked a Darwinist: "Why should daffodils have exactly 6 petals, regularly arranged, all of the same shape, size, and color? After all, the number of a priori possible arrangements that include irregular configurations must be of a higher order of infinity than that of the set of those restricted to regular arrangements, so why should purely random mutations settle finally on a regular arrangement?"
He replied that it was selectively advantageous. I asked in what way. He said that he didn't know.
Of course, one might argue that since there are no details there can be no devil.
Similar considerations raise doubts about the applicability of the NDT to many familiar topics, e.g., the peppered moth. How did the first typica morph arise? Some photographs show an astonishing match between the color, shades, and patterns of typica and a background lichen-covered tree trunk. If the NDT applied, there must presumably have been a large (but unknown) number of evolutionary steps at each of which there were a large (but unknown) number of PAMs of unknown types which were subject to natural selection by unknown means. Presumably these PAMs covered a wide range of possible patterns, colors, and shades, of which one and only one set was adaptive (for unknown reasons). This kind of hypothesis seems a priori to be less probable than one invoking some type of mechanism akin to that involved in chameleons' matching of background.
“There are philosophical or methodological objections to evolutionary theory. They have been very well voiced by Professor Karl Popper that the current neo-Darwinian Theory has the methodological defect of explaining too much. It is too difficult to imagine or envisage an evolutionary episode which could not be explained by the formulae of neo-Darwinism”. Sir Peter Medawar (p.xi)
“All I want to say is that most of this research dealt only with two factors, mutation and selection, in other words, the original Darwinian model. Popper is right; this model is so good that it can explain everything, as Popper has rightly complained.” Ernst Mayr (p.47)
“Mathematical Challenges to the Neo-Darwinian Interpretation of Evolution”, WISTAR Symposium, eds. Moorehead and Kaplan, (June 1967; 2nd printing Oct. 1985; Alan R. Liss, Inc., New York, NY 10003)