Hmmm let me think.........
Precipitation would help distribute water all over the earth's surface, which gives animals and humans a source for water. Precipitation also helps plants grow which in turn provides humans with fresh air. Evaporation also benefits the different living organisms on earth by purifying the water. When water evaporates, pollutants are filtered and left behind , which makes it cleaner during precipitation.
Because good researchers rely on first hand account or better said primary evidence. The reason why they rely on primary evidence is because it is usually the most reliable. Much more so than secondary or even tertiary evidence. This enables them to understand the history of a certain topic better.
Answer:
Overpopulate
Explanation
Because they would interact with each other positively.