Contents
- What the Weasel Program Does
- Problem 1 — Natural Selection Is Absent
- Problem 2 — The Junk DNA Argument Has Collapsed
- Problem 3 — Where Are the Transitional Fossils?
- Problem 4 — The Program Presupposes a Designer
- Problem 5 — Mutations Are Not Random and Uniform
- Another Angle: The Problem of Probability
- DNA's Information Storage Capacity
- Conclusion
What the Weasel Program Does
Dawkins begins with a question: if a monkey typed randomly, what are the odds of producing the Shakespeare phrase "METHINKS IT IS LIKE A WEASEL" (28 characters)? Using an alphabet of 27 characters (26 letters plus a space), the probability of getting all 28 positions correct in a single attempt is roughly 1 in 27²⁸ — approximately 1 in 10⁴⁰. He calls this single-step selection, and rightly notes that natural selection does not work this way.
His alternative is cumulative selection, demonstrated by the Weasel program. The algorithm works as follows:
The Weasel Algorithm
① Start with a random 28-character string.
② Generate many copies of that string, each with random mutations applied.
③ Select the copy closest to the target phrase ("METHINKS IT IS LIKE A WEASEL").
④ Repeat. Each character represents an amino acid; the completed phrase represents a functional protein.
Dawkins reports reaching the target phrase in just 43 generations. Below is the actual output.
The simulation is mathematically correct. The question is whether it models actual biological evolution. The following five points examine this.
Problem 01 Natural Selection Is Absent — Intermediate Forms Cannot Survive
Evolution operates through two mechanisms: random mutation and natural selection. The Weasel program simulates only the first, effectively eliminating the second.
Consider Generation 1:
This string contains no meaningful information. Translated into biological terms, it represents an amino acid sequence with no functional proteins whatsoever. Such a structure cannot perform any biological function. If natural selection were actually operating, this organism would be eliminated immediately — before reproducing.
Yet the Weasel program uses this string as the parent of the next generation and carries it forward. It assumes all intermediate stages survive to reproduce, without any selection pressure removing non-functional forms.
If the "completed WEASEL" organisms were eventually eliminated by natural selection, why did the non-functional intermediates survive long enough to produce them? The Weasel program offers no answer to this.
Problem 02 The Junk DNA Argument Has Collapsed
Look at Generation 30:
Meaningful fragments ("METH", "IT", "LIKE") sit alongside meaningless ones ("INGS", "ISW", "WECSEL"). If this analogy maps to biology, then every organism at an intermediate stage of evolution should contain vast quantities of non-functional DNA sequences.
Dawkins was, for many years, a prominent advocate of junk DNA — the idea that most of the genome serves no function and is simply evolutionary debris. This was a natural prediction of the Weasel model: you would expect large amounts of biological "noise" accumulating alongside functional sequences.
However, the 2012 ENCODE project found that approximately 80% of the human genome has at least one biochemical function. Subsequent research has continued to identify regulatory roles, RNA structural functions, and cell differentiation signals in sequences previously labeled as "junk." The junk DNA argument is under significant revision.
ENCODE Project (2012)
While only ~1.5% of the human genome directly encodes proteins, approximately 80% of the genome shows evidence of biochemical activity — including transcription factor binding, chromatin structure, and regulatory function. Sequences long dismissed as "junk" are increasingly found to have specific roles.
Problem 03 Where Are the Transitional Fossils?
If the Weasel analogy is valid, the fossil record should show continuous, gradual transitions between forms. Given that the program is a radical simplification of actual evolution, real species transitions would require far more intermediate stages — meaning far more transitional fossils should be discoverable.
The evolutionary trees that adorn our textbooks have data only at the tips and nodes of their branches; the rest is inference, however reasonable, not the evidence of fossils. — Stephen Jay Gould, Professor of Paleontology, Harvard University, Natural History, Vol. 86, No. 6 (1977), p. 13
Gould was not rejecting evolution. He was one of its most prominent defenders. But he openly acknowledged that the fossil record does not provide the continuous gradual evidence the standard model predicts. His proposal of punctuated equilibrium was an attempt to explain this gap.
The problem extends beyond fossils. If the Weasel logic holds, the living world should contain far more incomplete organisms than complete ones: creatures with half-formed wings, partially developed eyes, hearts not yet connected to nervous systems. We do not observe this in the natural world.
Problem 04 The Program Presupposes a Designer
Dawkins repeatedly emphasizes a central claim: evolution has no direction and no purpose. Natural selection does not "aim" to build an eye or a brain. It simply preserves what happens to work better right now.
The Weasel program contradicts this premise.
How does the program know which letters in this string are "correct" and which are not? Because the target phrase — "METHINKS IT IS LIKE A WEASEL" — was programmed in advance. Without a pre-specified goal, there is no basis for deciding which letter at which position should be preserved and which should be changed.
A process that converges on a predetermined goal is not evolution — it is optimization. Optimization requires a designer who sets the objective function. The Weasel program, paradoxically, models a goal-directed process — the very thing evolutionary theory claims to explain away.
Dawkins Asked About Genetic Information Increase
In the video below, Dawkins is asked to provide an example of a mutation that has added new genetic information — a central requirement of evolutionary theory. His response speaks for itself.
Problem 05 Mutations Are Not Random and Uniform
The Weasel program assumes mutations are applied randomly and uniformly across all positions. Real genomic mutation does not work this way.
① Mutational Bias
Substitutions between the four DNA bases (A, C, G, T) do not occur with equal probability. Transition mutations (purine↔purine or pyrimidine↔pyrimidine) are significantly more common than transversions. This bias substantially restricts the sequence space that mutation can realistically explore.
② Mutation Hot Spots
Mutations are not distributed evenly across the genome. Specific positions — "hot spots" — experience mutation at far higher rates than surrounding regions.
TP53 Gene Mutation Distribution
The TP53 tumor suppressor gene has been studied extensively in cancer research. Approximately 70% of TP53 mutations occur at just a handful of hot spot codons (positions 175, 248, 249, 273, and a few others) out of more than 1,000 base pairs. In separate studies, 94.4% of observed mutations across a 319-base-pair region occurred at only 2 positions.
Applied to the Weasel analogy: the positions that can change are limited, and the changes that occur are biased toward specific substitutions. This is fundamentally different from the uniform random mutation the program assumes.
More fundamentally, this calls into question whether point mutation accumulation can account for the vast genetic differences observed between related species.
Human–Chimpanzee Genome Difference: What the Data Actually Shows
2005 Nature (Chimpanzee Sequencing and Analysis Consortium):
Comparison of the human and chimp genomes identified approximately
35 million single-nucleotide differences,
5 million insertion/deletion events, and numerous chromosomal rearrangements.
The commonly cited "1% difference" refers only to SNPs in alignable regions.
2025 Nature (Yoo et al., April 9, 2025):
Unlike previous studies that used the human genome as a scaffolding template,
this research sequenced primate genomes fully from scratch.
The result: 12.5–13.3% of the human genome is either unalignable
with the chimp genome or present in only one of the two.
Adding SNP differences, the total divergence reaches ~14–14.9%,
equivalent to approximately 448 million nucleotide differences.
This is 14 times greater than the "1% difference" widely cited in textbooks and museums.
The accumulation of point mutations through mechanisms like those modeled in the Weasel program cannot plausibly account for a divergence of this magnitude.
Another Angle: The Problem of Probability
100 Coin Flips
A person can arrange 100 coins in any chosen order in a few minutes. But what if you had to achieve the same sequence by flipping coins at random?
flipping once per second
to expect one success
This is for a 1/2 probability event repeated 100 times. A functional protein requires hundreds of amino acids in a precise sequence, each of the correct type at the correct position.
Can We Turn a Fly Into a Chimpanzee?
With current biotechnology, can humans synthesize a fly from scratch? No. We cannot independently create any organism even simpler than a fly.
Now suppose we start with a fly and, with the complete chimpanzee genome map in hand, attempt to engineer the fly into a chimpanzee through directed genetic editing. Could we do it? No — not with any existing technology. We know the target. We have a map. We have intelligent direction. And we still cannot do it.
If a directed, intelligent process with a complete roadmap cannot accomplish this, how should we evaluate the claim that undirected random mutation — with no target, no map, no guiding hand — transformed single-celled organisms into human beings?
DNA's Information Storage Capacity
A separate measure of biological complexity is the information density of DNA itself.
density circa 2015
storage density of DNA
storage density
In 2001, Samsung developed the world's first 4GB DRAM chip — enough for 640 books. By 2004, an 8GB chip held ~20,000 books. By 2015, chips could store the equivalent of 2 million books. Yet a DNA strand scaled to the same physical size would hold the equivalent of roughly 20 trillion books.
The best information-storage technology humans had produced as of 2015 was over one million times less dense than DNA — which is said to have emerged through undirected mutation over hundreds of millions of years.
Human engineering has repeatedly advanced by studying and copying biological systems. This practice — biomimicry — presupposes that there is something in nature worth copying: a pre-existing design sophisticated enough to improve on what human ingenuity has produced.
Conclusion
The Weasel program is mathematically valid as a simulation. But as a model for evolutionary information generation, it fails on five counts:
Five Problems with the Weasel Program as an Evolutionary Model
① Natural Selection Absent — Intermediate forms that cannot function
would be eliminated by natural selection before reproducing.
② Junk DNA Prediction Fails — The model predicts vast non-functional
genomic sequences, but genome research increasingly contradicts this.
③ Fossil Record Gap — Continuous intermediate fossil sequences predicted
by the model are not found; even leading evolutionary paleontologists have acknowledged this.
④ Teleological Design Presupposed — The program's pre-set target
makes it a model of goal-directed optimization, not undirected selection.
⑤ Mutation Model Oversimplified — Real mutations are biased and
hot-spot concentrated, not uniformly random as the program assumes.
What the Weasel program actually demonstrates is a goal-directed convergence process run by an intelligent agent who set the target, writes the selection rules, and runs the simulation. This is not evidence against design. If anything, it illustrates why design is a coherent inference when we encounter complex, specified information in biology.
The goal of this analysis is not to dismiss evolutionary biology wholesale, but to evaluate whether the Weasel program succeeds as an argument for undirected information increase. On the evidence examined here, the structural assumptions required for the program to work are precisely the assumptions that real evolutionary theory cannot make.
References
- Richard Dawkins, The Blind Watchmaker (1986), W.W. Norton & Company
- Richard Dawkins, Climbing Mount Improbable (1996), W.W. Norton & Company
- Stephen Jay Gould, "Evolution's Erratic Pace," Natural History, Vol. 86, No. 6 (1977), p. 13
- ENCODE Project Consortium, "An integrated encyclopedia of DNA elements in the human genome," Nature 489 (2012): 57–74
- The Chimpanzee Sequencing and Analysis Consortium, "Initial sequence of the chimpanzee genome and comparison with the human genome," Nature 437 (2005): 69–87
- Yoo et al., "Complete sequences of ape genomes," Nature (April 9, 2025) — 12.5–13.3% of human genome unalignable with chimp; total divergence ~14–14.9%
- IARC TP53 Database, International Agency for Research on Cancer
- George Church et al., "Next-Generation Digital Information Storage in DNA," Science 337 (2012): 1628