Researching Mechanisms of Biological Evolution

Evolution is the process by which modern organisms have descended from past organisms. It can cause organisms to look alike or create life with a great amount of diversity. Why do some organisms evolve quickly, while others evolve slowly? Is evolution a matter of chance, or are their specific factors that lead the way for evolution to take place?
Using at least one credible online source, research two evolutionary mechanisms of your choice. A mechanism is a process or technique for achieving a set result. Using the evidence from your research, explain how the mechanisms that you chose can impact the evolution of a species