Does A Darwinian Evolution Have The potential To Generate Average-Sized Functional Enzymes?

Does an unplanned evolution have the potential to generate a gene coding for the first member of a new family of average-sized functional enzymes?

First of all, average-sized enzymes are composed of 300 to 400 amino acid residuals.¹ The probability of generating a gene coding for a specific enzyme of 101 amino acid residuals is 2 chances in 10⁶⁵ tries.² The probability of generating a gene coding for a specific enzyme of 150 amino acid residuals is about 1 chance in 10⁷⁷ tries.³

So, how many tries does a Darwinian evolution provide? The number of tries is the total number of mutations provided by all organisms ever existent. Since such a number is unknown and unknowable, a generous estimate of this number will suffice.

Nature has three domains: prokaryotes (bacteria), eukaryotes, and archaebacteria. Prokaryotes are in the majority.⁴ Prokaryotes produce about 1.7x10³⁰ cells per year.⁵ Since evolution began less than 4 billion years ago, there have been fewer than 6.8x10³⁹ prokaryotes. This number can be rounded up to fewer than 10⁴⁰ prokaryotes.

Since prokaryotes are in the majority, the domains of eukaryotes and archaebacteria are in the minority; they both have had fewer than 10⁴⁰ individual organisms. Therefore, the total number of organisms from the three domains is less then 3x10⁴⁰ organisms.

The mutation rates for these organisms is less than 1,000 (10³) heritable mutations per organism per replication. Together, all organisms ever existent have had a total of fewer than 3x10⁴⁰ x 10³ mutations or 3x10⁴³ mutations. Each heritable mutation is one try at the generation of a gene coding for the first member of a new family of enzymes. This is the one and only set of mutations.

  As noted, the probability of generating a gene coding for a specific enzyme of 101 amino acid residuals is 2 chances in 10⁶⁵ tries. So, what is the overall potential of 3x10⁴³ mutations or tries? Multiplying the probability times 3x10⁴³ mutations or tries gives the answer:

       2 chances / 10⁶⁵ tries x  <3x10⁴³ tries =  <6 chances / 10²²            

<6 chances / 10²²  = <1 chance in 1.66x10²¹

  So, the overall probability of generating a gene coding for a specific enzyme of 101 amino acid residuals using all mutations since the onset of the evolutionary process is less than one chance in a billion trillion.

What is the overall probability of generating a gene coding for a specific enzyme of 150 amino acid residuals with 3x10⁴³ mutations or tries? The probability of generating a gene coding for a specific enzyme of 150 amino acid residuals is about 1 chance in 10⁷⁷ tries. Again, this probability is multiplied by  3x10⁴³ mutations or tries:

1 chance /10⁷⁷ tries x <3x10⁴³ tries = <1 chance in 3.3x10³³

Here the overall probability of generating a gene coding for a specific enzyme of 150 amino acid residuals with fewer than 3x10⁴³ mutations or tries is less than one chance in 3 billion trillion trillion.

Evolution is never prescient. Therefore, there is no such thing as a "beneficial accumulation" prior to a proto-gene becoming minimally active. But, the probability of such a gene being generated is exceedingly small, and natural selection cannot select for enzymes and protein structures that were never generated. The "beneficial accumulation" of Richard Dawkins occurs only after the onset of beneficial enzymatic activity.

The number of mutations ever existent in a Darwinian evolution is insufficient, by many orders of magnitude, in exploring sequence space. Natural selection cannot select for genes that were never generated. Since an unplanned Darwinian evolution does not have the potential to generate genes coding for specific enzymes of 101 and 150 amino acid residuals, it does not have the potential to generate those genes coding for specific average-sized functional enzymes associated with metabolism, reproduction, macroevolution, and the origin of species. Thinking that it does have the potential is illogical, irrational, and unscientific.

The oft reported unplanned Darwinian evolution of a cell of common ancestry into a primitive chordate, a primitive chordate into a fish, fish into amphibians, amphibians into reptiles, reptiles into birds, and reptiles into mammals is a colossal myth.

Endnotes:

1. S. Carroll, The Making of the Fittest, New York: W.W. Norton & Co., 2006, 74.

2. H. P. Yockey, “A calculation of the probability of spontaneous biogenesis by information theory.”  J. Theor. Bio., 67 (1977), 387.

            &

J. Reidhaar-Olson and R. Sauer, “Functionally Acceptable Substitutions in Two α-Helical Regions of λ Repressor.” Proteins: Structure, Function, and Genetics, 7 (1990), 315.

3. D. Axe, “Estimating the Prevalence of Protein Sequences Adopting Functional Enzyme Folds,” Journal of Molecular Biology 2004 Aug 27; 341 (5): 1295-1315.

4. W. Whitman, D. Coleman, and W. Wiebe, “Prokaryotes: The unseen majority,” Proc. Nat. Acad. Sci., 95, June 1998.

5. Ibid, Table 7, 6581, and abstract, 6578.

Fredric P. Nelson, M.D. © 2025