This Keeps The Species From Getting Out Of Control It's A Chain Of Life. Species Have To Reproduce To Feed Other Species. This In Turn Allows A Species To Grow And Reproduce Because It Was Kept Fed By Other Species That Was Different
Well the ecosystem requires a precise and delicate balance to keep it in check. Ok lets say that you are in a grassy field with bugs, mice, snakes, plants, birds, etc. If any single animal reproduces too slowly, it will cause others to starve or die off, and if any single animal reproduces too quickly than it will quickly overtake and destroy the local ecosystem. Ok you have plants. Bugs come to eat the leaves of the plants. The mice eat the bugs, the snakes eat the mice, and the hawks eat the snakes. So, if the mice for example were unable to reproduce, then the entire local ecosystem would collapse. Without the mice, the bug population would explode and eat away all of the plants. When they eat away all of the plants, then they will die. Also there would be no food for snakes so they would die, and when the snakes die the hawks would die. Using that same example, imagine if the mice started reproducing too quickly. When the mice population explodes, they will eat away all of the bugs. When they eat away all of the bugs, the mice will have no more food and they will die. When the mice die, then the snakes will die, and when the snakes die the hawks will die. So for an ecosystem to maintain its biodiversity, organisms need to be able to reproduce fast enough to replace those that die, but at the same time, it needs to be slow enough so that they don't eat away their entire food supply.