(A) Who is having more species diversity - Columbia or Greenland and why? (B) Explain the concept proposed by Paul Ehlrich.

Columbia, as it is located near the equator / as we move from equator towards poles the biodiversity decreases.

Paul Ehrlich gave rivet popper hypothesis in an airplane (ecosystem) all parts are joined together using thousands of rivets (species), If every passenger travelling starts popping a rivet to home (causing a species to become extinct) it may not affect flight safety (ecosystem functioning) initially, but as more and more rivets are removed, the plane becomes dangerously weak over a period of time, furthermore which rivet is removed may also be critical loss of rivets on wings (key species) is more serious threat to flight safety.