Darwin's theory of evolution

Today, I learn some new information about Darwin's theory of evolution. There are 5 keys in it. First of all, species have great fertility , they make more children grow up adults. The second key is population remain roughly the same size. The third is food resources are limited. The next is that in sexually reproducing species, generally no two individuals are same. The last one is that much of this variation is heritable. So to sum up, this evolution includes variation, competition, offspring, genetics, and natural selection.