Why Natural Selection Occur

Natural selection occurs in nature obviously. There are quite a few reasons natural selection happens. One of the reasons natural selection occurs is because sometimes more offspring are born but not all of them survive. If every single off spring would survive there would be a huge population explosion of that species. Another way natural selection occurs is having different reproduction and survival rates. Also mutations are another reason for natural selection sometimes if a mutation is created those animals with new mutation will either prosper or die off right away. A extremely good example of natural selection is the medium ground finches in the Galapagos Islands. At one point in time there was a drought that only left certain types