Darwin's evolution theory explains organisms change accordingly.
Explanation:
Darwin traveled the world sitting on a five year voyage , during his journey he collected various species of plants as well as animals. He also came across three different types of diversity that are globally, locally, species overtime. Darwin said as earth is an oldest planet various changes have occurred from and still going on in present. Darwin said Farmers choose organisms based on traits and humans choose base on their needs. Four things essential for natural selection are competition, adaptation, variation, fitness.