Sugar.....................
Answer:
availability of resources.
Explanation:
Availability of resources is abiotic factor which is responsible for the decrease in population in 1990 because when the population reaches its carrying capacity so the organisms compete with each other and due to limited resources such as food etc the decrease occurs in population. Infection is also occurs when there is high population due to which death occurs and population of organism decreases.
Evolution would least likely be a cause of natural selection.
Natural selection has to do with the survival of the fittest. Therefore, adaptation, variation, and overpopulation all have an impact on natural selection - those who do not adapt to their new surroundings due to overpopulation or those whose bodies have not modified enough will not survive.
Answer:
helps ecosystem
Explanation:
provides oxygen, clear water and air, water treatment and the list goes on
