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

Classification and evolution are highly interlinked fields of study.

Classification

Classification is influenced by evolution. The modern classification system is also called phylogenetic classification, which means it is based on evolutionary relationships.  Organism classification is based on the relative similarities and differences between the species. Resemblances of humans are because they evolved from a common ancestor, and their differences are due to adaptations to various types of climate.

Evolution

The definition of evolution suggests that species can be graded to increase complexity. According to Darwin contribution to the theory of evolution, the organisms which existed years ago had undergone certain changes for better survival, and new life forms have arisen from them.

Thus, it is concluded that the evolution and classification of species are interlinked.