You can think of the ecosystem as a very big house composed of 40 million bricks. Every brick represents a unique species. And every day, around 120 bricks are removed from somewhere in the building as species become extinct.
"As more bricks are removed, cracks would develop in the walls, the roof would sag, and leaks would appear. At some point that we cannot predict, the entire structure would collapse and the house would turn to rubble."
Source: Clemson University
H/T Char Grainger