The Universal Failure of Fixation: MITTENS Applied Across the Tree of Life

The MITTENS framework (Mathematical Impossibility of The Theory of Evolution by Natural Selection) previously demonstrated a 220,000-fold shortfall between required and achievable fixations for human-chimpanzee divergence. A reasonable objection holds that this represents an anomaly—perhaps something about the human lineage uniquely violates the model's assumptions. We test this objection by applying MITTENS systematically across the tree of life: great apes, rodents, birds, fish, equids, elephants, and insects. Across 18 species pairs spanning generation times from two weeks (Drosophila) to 22 years (elephants) and divergence depths from 12,000 years (sticklebacks) to 100 million years (bacteria), we find that every sexually reproducing lineage fails by 2–5 orders of magnitude. The sole exception is Escherichia coli, which passes due to asexual reproduction (eliminating recombination delay), complete generational turnover (d = 1.0), and astronomical generation counts (~1.75 trillion over 100 MY). Rapid radiations thought to exemplify evolutionary potential—Lake Victoria cichlids (500+ species in 15,000 years), post-glacial sticklebacks—show among the largest shortfalls: 141,000× and 216,000× respectively. Short generation times, which should favor the standard model by providing more opportunities for fixation, do not rescue it. The pattern is systematic and universal. The substitution-fixation model fails not for one troublesome comparison, but for every sexually reproducing lineage examined. The mechanism of natural selection does not work.