Redundancy hypothesis states:
Redundancy means that multiple species can perform overlapping ecological functions. If one disappears, another member of the same functional group may partly compensate, buffering ecosystem processes until too many substitutes—or a nonredundant contributor—are lost. Biodiversity–function hypotheses differ in how they assign ecological importance among species. Complementarity emphasizes distinct contributions, redundancy emphasizes overlap and compensation, rivet theory emphasizes cumulative weakening, keystone theory emphasizes particular influential species, and idiosyncrasy emphasizes cont
Ref: NCERT Biology Class 12, Ch. 15 Biodiversity and Conservation