Abstract
In an ecosystem, the existence of any species of animals or plants solely depends on the capability to adapt to its environment. This is true because, those species which are poorly adapted become extinct. For example, trees that could not adapt to harsh conditions of the desert were eliminated and those species that were well adapted were spared. This is basically what is called natural selection (Jeff et al 9). Similarly, those animal species that could not adapt to any given environmental conditions of an ecosystem were easily eliminated out of existence. Human being, on the other hand, ...
