Question

explain with example how evolutionary relationship is linked to classification.

Answer 1

Classification involves the procedure of grouping organism into system, based on similarities in the internal and external structures (or evolutionary history).

Two species are more closely related if they share a lot of similar characteristics.

For instance, in a family, a brother and a sister are closely related and they have a common ancestor- their parents. Also, brother and his cousin brother are related but less than his sister. This is because, the brother and his cousin have a common ancestor i.e grandparents who are the second (or secondary) generation, whereas parents are the first (or primary) generation.

Answer 2

Classification is system to group organism into different classes in a formal system. If an organism has some character common among each other than they are more closely related.
For example, in a family, a brother and sister are closely related and they have a common ancestor i.e their parents.
A brother and his cousin are also related but less than brother and sister as they have common grandparents. 
Grandparents were second generation whereas parents are first generation.