Answer:
Evolution is the biological process that happens over time in a population, giving rise to new species. The theory of evolution states that all organisms alive on Earth today have a common ancestor which lived years ago.
Step-by-step explanation:
Evolution is one of the fundamental reason of diverse life on Earth today. Principally, this process takes place by changes in genetic elements via mutations and crossing-over. The positive changes (mutations) allow the organism to develop better condition in order to survive in changing environmment. However, if the changes takes place at major scale, it also leads to the creation/development of new species. To explain this further, I have added a photograph where we can see how different organisms were evolved in the history of Earth.