Illicit major

Biological Parallel

'No prokaryotes are multicellular. All prokaryotes are cells. Therefore, no cells are multicellular.' The major term (cells) is distributed in the conclusion but not the premise—an illicit major. The fallacy: generalizing beyond the evidence. Biological version: 'No bacteria form societies. All bacteria are single-celled. Therefore, no single-celled organisms form societies.' False—slime molds, dictyostelium aggregate. The error: assuming what's true of a subset holds for the category.