The only life function viruses can perform is what?

Without a host cell, viruses cannot carry out their life-sustaining functions or reproduce. They cannot synthesize proteins, because they lack ribosomes and must use the ribosomes of their host cells to translate viral messenger RNA into viral proteins.

Explanation:

the social historical theory explains the creation of the varnas, jats and of the untouchables. according to this theory, the caste system began with the arrival of the aryans in india. the aryans arrived in india around 1500 bc. the fair skinned aryans arrived in india from south europe and north asia.

i believe that the answer to the question provided above is that  establishing smaller ethnic communities within larger communities  gives more chance for people to know each other more but this might lead to the  conflict between groups.