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The Mystery of the Genome
a limited number of traits. They have done this by employing intelligent design in their experiments, to deliberately minimize noise. They have used blocking techniques, replication, statistical analysis, truncation selection, and highly controlled environments. Natural selection does none of this - it is by definition a blind and uncontrolled process – subject to unconstrained noise and unlimited random fluctuations. The genetic consequences of all this noise - When we realize that high levels of genetic noise are un-avoidable, we realize we cannot significantly shrink down the near-neutral box in Figure 3d – not even by invoking larger population sizes. As we come to appreciate that there are two entire levels of noise above and beyond gametic sampling, we realize that Figure 3d must be corrected (see Figure 9). Kimura’s “no-selection box” must be expanded very significantly, firstly based on the imperfect correlation between genotype and phenotype, and then secondly based upon the imperfect correlation between phenotype and reproductive success. The result of these two imperfect correlations is that the number of near-neutral (unselectable) nucleotide positions is much greater than commonly realized, and their abundance is not strictly dependent on population size. Small population size certainly aggravates the noise problem, but large population size cannot alleviate this problem (for more detailed discussion see Appendix 4). The pervasive existence of serious genetic noise amplifies virtually all my previous arguments regarding the limits of selection. Kimura’s near neutral box gets much bigger (Figure 9) - because huge numbers of otherwise minor mutations become near-neutral and hence un-selectable. The selection threshold problem, wherein simultaneous selection for too many traits results in a complete