Water supplies are being overdrawn in many parts of the world. No, not unless we cut down the population. We always hear about water shortages. It isn t fair to us. If water is scarce, animals and plants die.
Natural selection occurs.
If animals and plants live in dry regions, they evolve adaptations to deal with scarce water. Plants like the cactus, and animals like lizards and camels have evolved adaptations to survive with little water. People on the other hand, don t make adaptations to use less water. They use more. They find ways to extract more and more water.