Explain the five key points of DARWIN'S evolution theory?

1) There are more young born in a season than can actually survive.

2) This results in a struggle for existence as more and more organisms struggle for natural resources. (Built of Malthus's Principles that all environments possess a carrying capacity).

3) Within any given population, there will always be variation of some sort.

4) Only those best adapted, mutated or not, will survive. Only those best suited get the chance to pass on their genes.

5) Organisms do not change due to environmental pressure, rather the allele frequency alters within the population as needed.