In Chapter 1 of The Design Matrix, I note that there are only two non-teleological responses to the appearance of design in life. One response is to follow the lead of David Hume and deny the appearance of design. Yet multiple developments in cellular and molecular biology have rendered this a very unattractive response. As I noted:
Amorphous vessels and balloons filled with molasses would not arouse suspicions of design. But this is not what science has discovered. Modern science teaches us that “the cell is understood to be highly organized, with specialized areas for different functions and molecular motors shuttling components around.”11 Hume’s objection to Paley’s argument certainly has not been strengthened by scientific discovery.
That leaves us with the other response – follow the lead of Charles Darwin and propose an alternative, non-teleological explanation for the appearance of design. For example, Richard Dawkins gleefully concedes that biology is saturated with the appearance of design as he feels he can confidently label it all ‘designoid’ because natural selection, working on small variations, can and does account for it all.
Yet we have just seen that Dawkins is assuming an essence to natural selection that science does not support.
The blind watchmaker is not an omnipresent force sifting through every variation that turns up. And this is very significant because the blind watchmaker is the only plausible non-teleological explanation for the appearance of design, the only plausible designer-mimic.
As it turns out, the blind watchmaker is only a part-time worker. Many biological variations occur apart from any judgment of the blind watchmaker – neutral evolution. And even when it is time to recruit the blind watchmaker, it interacts with variations in two ways:
the dominant mode of selection is not the Darwinian positive selection of adaptive mutations, but stabilizing, or purifying selection that eliminates deleterious mutations while allowing fixation of neutral mutations by drift
Natural (positive) selection is an important factor of evolution but is only one of several fundamental forces and is not quantitatively dominant; neutral processes combined with purifying selection dominate evolution.
Let me quote from Watson’s text, Recombinant DNA, to help clarify the distinctions:
Mutations that are deleterious, such as the protein truncation described above, reduce the chance that the individual will reproduce and are removed from populations. This type of selection is often called purifying or negative selection…On the other hand, mutations that improve an organism’s chances of survival and reproduction – disease resistance is a good example – are beneficial and become more prevalent in a population. This type of selection is often referred to as positive or adaptive selection. There are also neutral mutations that are neither deleterious nor advantageous and are not under selective pressure; these mutations, which make up many of the genetic differences between species, are said to “drift” with in population.
So why is this all significant? I have argued that natural selection is a designer-mimic; the blind watchmaker. Yet the examples I used in The Design Matrix (industrial melanism and PCP degradation) are examples of positive or adaptive selection.
Yet as you should be able to see by now, evolution is not under the constant supervision of a designer-mimic. On the contrary, we have three levels of supervision:
Level 1: Neutral. Variation is neutral and invisible to natural selection.
Level 2: Purifying selection. Variation occurs and natural selection responds not as a designer-mimic, but as a trash man, removing the variation from the population.
Level 3: Adaptive selection. Variation occurs in such a way that natural selection takes on the role of a designer-mimic and begins to shape some members of the population so they are better adapted to the environment.
Once we realize the three levels of involvement for natural selection, we can begin to ponder some more questions:
1. What dynamics determine whether natural selection behaves as a trash man or a blind watchmaker?
2. While strict gradualism may not be the principal regime of evolution, is it required for the blind watch maker to behave as a designer-mimic?
3. If only adaptive selection can mimic a designer, are there examples of appearance of design that emerged under Levels 1 or 2?
If candidates are found for question 3, we would have an appearance of design without a non-teleological explanation/response from neither Hume nor Darwin.