How did the Caste System evolved?

Well , I'll show first what is Caste System is all about. The indian Caste System describes the system of social stratification and social restriction in Indian subcontinent in which social classes are defined by thousands endogamous heredity groups, often termed jatis or caste. Within a jati there exists a exogamous groups known as gotras. There are many social stratifications of indian Caste System. The nobles, scribes, artisans, peasants and slaves. A stratified and hierarchical socio-economic organization of society that evolved as Indian's ancient civilization with it's social order,moral and ritual codes absorbed the nomadic, sanskrit speaking aryan population.