Little Dragon
Well-Known Member
Survival of the fittest is not a good descriptive term for the process it describes.Everybody on the planet knows what survival of the fittest means.
Organisms, in any ecological niche, survive, or rather live long enough to reproduce, do so by adapting to that ecological niche. They do this by having physical advantages over other competitors for their niches.
For example, animals that inhabit islands and island chains, over many generations, often become much smaller than the founding population. This phenomenon is widespread and known as Island Dwarfism, it has even affected members of the Homo genus. Homo Floresiensis, whom were mostly under 1.2 m tall. They inhabited the island of Flores in Indonesia about 50000 years ago.
They become smaller and weaker, because that is a successful adaptation on an island, where there are few if any large natural predators. No need to waste energy building unnecessary body mass, to fight off predators when competing with them or when becoming prey themselves.
Conversely, regions with lots of predators, cause the opposite evolutionary response, and an increase in the size of prey animals. African mega fauna, like Elephants and Rhinos, are a good example.