Concept · Cognitive Bias: Formal logical fallacies
Modal fallacy
Origin: Traditional logic
Biological Parallel
'It is possible for a mutation to arise. Therefore, it is necessary that it will arise.' This confuses possibility with necessity—the modal fallacy. Evolutionary theory shows: most possible mutations never occur (genetic search space is infinite, populations finite). Convergent evolution demonstrates: when a solution is necessary, it arises independently multiple times (camera eyes evolved 50+ times). Possibility doesn't guarantee occurrence; necessity manifests through repeated convergence.