Theory 28/Evolution

Eye Loss Is Saving Against Cost

The claim

Eye regression in cave fish proceeds only when the ratio of energetic saving to pleiotropic cost exceeds one, so some cave populations retain eyes because losing them would break something else.

01Mechanism

Eyes are expensive and useless in darkness, but the same genes pattern other structures; the ratio determines whether selection favours loss.

02Predictions

P1Regression should vary with pleiotropy.
P2Time in cave alone should mispredict.

03Refutation

Regression tracking cave age would remove the cost term.

04Why it resists the grid

Trait loss is the phenotype, and the gene that causes it is doing two jobs — neither 'adaptation' nor 'degeneration' fits.