Natural Selection is the process by which random evolutionary changes are chosen for by nature in a normal, same, orderly, non-random way. An example is the Main Land Tortoise and Island Tortoises. A Tortoise from the main land might have possibly traveled on a raft to get the the island. Once it arrived it laid its eggs. After thousands of years, because of random changes caused by decent with modification eventually transformed the island creatures and the main land creatures so much that they can no longer be considered the same species. The Tortoises wasn’t only randomly different to ancestors but they were specially adapted to their environment.