Original sentence: The school board claims there are "gaps" in evolution, which it claims is a theory rather than established fact, and that students have a right to consider other views on the origins of life
Edited sentence: The school board claims there are "gaps" in evolution, which it claims is a theory rather than established fact (most biologists claim that evolution is a factual phenomenon explained by the theory), and that students have a right to consider other views on the origins of life (many biologists claim that the theory of evolution explains biodiversity, not the origins of life; see abiogenesis)