Consider our planet represented by a jumbo jet. Each of the millions of rivets holding the fuselage together represents an individual species. Losing a species equates to popping a rivet from the jet. Hundreds, perhaps thousands of rivets could be popped out at random, and the jet will continue to function as a whole. But if the process is allowed to continue, pieces of the fuselage will start to loosen and rattle. Inevitably, as this “extinction” process continues, a chunk of the jet will fall off. We know what happens next: collapse. The entire system goes down.
