How are the areas of study-evolution and classification-interlinked?

Classification involves grouping of organism into a formal system based on similarities in internal &external structure/ evolutionary history. Two species are said to be closely related if they have more characteristics in common which is only possible when they have common ancestor. With generations, an organism adapts according to its environment and becomes different from its ancestor. Classification of an organism is on the bases of their resemblance which is similar to makig an evolutionary history.