What is the "rivet popper hypothesis" used by Stanford ecologist Paul Ehrlich?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → An analogy comparing an airplane to an ecosystem and rivets to species.
Paul Ehrlich explained why the loss of species matters through an analogy. Losing rivets on the wings (key species that drive major ecosystem functions) is far more serious than losing a few on the seats or windows.
Option (1) An analogy comparing an airplane to an ecosystem and rivets to species. — Correct. This is the rivet popper hypothesis. In this analogy the species are the rivets and the ecosystem is the plane.
Option (2) A theory about the impact of invasive species on ecosystem health. — Incorrect. The effect of invasive species is a separate topic, alien species invasions, one of the causes of biodiversity loss (for example, the Nile perch in Lake Victoria). It is not the rivet popper idea.
Option (3) A hypothesis about the importance of biodiversity for human survival. — Incorrect. The book does say that rich biodiversity is needed for human survival. The rivet popper hypothesis, however, is the airplane analogy about species and ecosystem functioning.
Option (4) A concept related to the productivity of ecosystems and their resilience. — Incorrect. The link between species richness, productivity and stability comes from David Tilman’s long-term experiments on outdoor plots, not from Ehrlich’s analogy.
NCERT Extract:
The Importance of Species Diversity to the Ecosystem – “… There are no direct answers to such näive questions but we can develop a proper perspective through an analogy (the ‘rivet popper hypothesis’) used by Stanford ecologist Paul Ehrlich. In an airplane (ecosystem) all parts are joined together using thousands of rivets (species). If every passenger travelling in it starts popping a rivet to take home (causing a species to become extinct), it may not affect flight safety (proper functioning of the ecosystem) initially, but as more and more rivets are removed, the plane becomes dangerously weak over a period of time.”