Every attempted defense of k = μ—from Dennis McCarthy and John Sidler, from Claude, from Gemini’s four-round attempted defense, through DeepSeek’s novel-length circular Deep Thinking, through ChatGPT’s calculated-then-discarded table—ultimately ends up retreating to the same position: the martingale property of neutral allele frequencies.
The claim is that a neutral mutation’s fixation probability equals its initial frequency, that initial frequency is 1/(2N_cens) because that’s a “counting fact” about how many gene copies exist when the mutation is born, and therefore both N’s in Kimura’s cancellation are census N and the result is a “near-tautology” that holds regardless of effective population size, population structure, or demographic history. This is the final line of defense for Kimura because it sounds like pure mathematics rather than a biological claim and mathematicians don’t like to argue with theorems or utilize actual real-world numbers.
So here’s a new heuristic. Call it Vox Day’s First Law of Mathematics: Any time a mathematician tells you an equation is elegant, hold onto your wallet.
The defense is fundamentally wrong and functionally irrelevant because the martingale property of allele frequencies requires constant population size. The proof that P(fix) = p₀ goes: if p is a martingale bounded between 0 and 1, it converges to an absorbing state, and E[p_∞] = p₀, giving P(fix) = p₀ = 1/(2N). But frequency is defined as copies divided by total gene copies. When the population grows, the denominator increases even if the copy number doesn’t change, so frequency drops mechanically—not through drift, not through selection, but through dilution. A mutation that was 1 copy in 5 billion gene copies in 1950 is 1 copy in 16.4 billion gene copies in 2025. Its frequency fell by 70% with no evolutionary process acting on it.
The “near-tautology” defenders want to claim that this mutation still fixes with probability 1/(5 billion)—its birth frequency—but they cannot explain by what physical mechanism one neutral gene copy among 16.4 billion has a 3.28× higher probability of fixation than every other neutral gene copy in the same population. Under neutrality, all copies are equivalent. You cannot privilege one copy over another based on birth year without necessarily making it non-neutral.
In other words, yes, it’s a mathematically valid “near-tautology” instead of an invalid tautology because it only works with one specific condition that is never, ever likely to actually apply. Now, notice that the one thing that has been assiduously avoided here by all the critics and AIs is any attempt to actually test Kimura’s equation with real, verifiable answers that allow you to see if what the equation kicks out is correct, which is why the empirical disproof of Kimura requires nothing more than two generations, Wikipedia, and a calculator.
Here we’ll simply look at the actual human population from 1950 to 2025. If Kimura holds, then k = μ. And if I’m right, k != μ.
Kimura’s neutral substitution rate formula is k = 2Nμ × 1/(2N) = μ. Using real human census population numbers:
Generation 0 (1950): N = 2,500,000,000 Generation 1 (1975): N = 4,000,000,000 Generation 2 (2000): N = 6,100,000,000 Generation 3 (2025): N = 8,200,000,000
Of the 8.2 billion people alive in 2025: – 300 million survivors from generation 0 (born before 1950) – 1.2 billion survivors from generation 1 (born 1950-1975) – 2.7 billion survivors from generation 2 (born 1975-2000) – 4.0 billion born in generation 3 (born 2000-2025)
Use the standard per-site per-generation mutation rate for humans.
For each generation, calculate: 1. How many new mutations arose (supply = 2Nμ) 2. Each new mutation’s frequency at the time it arose (1/2N) 3. Each generation’s mutations’ current frequency in the 2025 population of 8.2 billion 4. k for each generation’s cohort of mutations as of 2025
What is k for the human population in 2025?
The application of Kimura is impeccable. The answer is straightforward. Everything is handed to you. The survival rates are right there. The four steps are explicit. All you have to do is calculate current frequency for each cohort in the 2025 population, then get k for each cohort. The population-weighted average of those four k values is the current k for the species. Kimura states that k will necessarily and always equal μ.
k = 0.743μ.
Now, even the average retard can grasp that x != 0.743x. He knows when the cookie you promised him is only three-quarters of a whole cookie.
Can you?
Deepseek can’t. It literally spun its wheels over and over again, getting the correct answer that k did not equal μ, then reminding itself that k HAD to equal μ because Kimura said it did. ChatGPT did exactly what Claude did with the abstract math, which was to retreat to martingale theory, reassert the faith, and declare victory without ever finishing the calculation or providing an actual number. Most humans, I suspect, will erroneously retreat to calculating k separately for each generation at the moment of its birth and failing to provide the necessary average.
Kimura’s equation is wrong, wrong, wrong. It is inevitably and always wrong. It is, in fact, a category error. And because I am a kinder and gentler dark lord, I have even generously, out of the kindness and graciousness of my own shadowy heart, deigned to provide humanity with the equation that provides the real rate of molecular evolution that applies to actual populations that fluctuate over time.
Quod erat fucking demonstrandum!
DISCUSS ON SG