Appendix 1
Kimura’s Quandary
Kimura, M. 1968. Evolutionary rate at the molecular level. 217:624-626.
161
Nature
“… in the evolutionary history of mammals, nucleotide substitution has been so fast that, on average, one nucleotide pair has been substituted in the population roughly every two years. This figure is in sharp contrast to Haldane’s well-know estimate … a new allele may be substituted in a population every 300 generations…”. “ at the rate of one substitution every two years… the substitutional load becomes so large that no mammalian species could tolerate it…”. “This brings us to the rather surprising conclusion … the mutation rate per generation for neutral mutations amounts to roughly … four per zygote…”. Kimura’s estimate of the actual mutation rate was 25-100 fold too low. But it is amazing how easily evolutionary theorists can accommodate any new data - they seem to have an infinitely flexible model - allowing continuous and unlimited development/revision of their many scenarios. Kimura, M. The Neutral Theory of Molecular Evolution. Cambridge University Press. p.27. “This formula shows that as compared to Haldane’s formula the cost is larger by about 2… under the assumption that the majority of mutation substitutions at the molecular level are carried out by positive selection… to maintain the same population number and still carry out mutant substitutions … each parent must leave … 3.27 million offspring to survive and reproduce. This was the main argument I used when I presented the neutral mutation-random drift hypothesis of molecular evolution…”. Kimura realized that Haldane was correct, and that selection must occur extremely slowly, and that it can only affect a limited number of mutations simultaneously. Kimura also realized that all the evolutionists of his time were evoking too much selection for too many loci, leading to absurd costs (more than 3 million offspring selected away - for every adult!?). He developed his neutral theory in response to this overwhelming evolutionary problem. Paradoxically, his theory led him to believe that most mutations are un-selectable, and therefore