Why Do We Need Last Name/family Name In Today's World?

I'm calling dibs on prime numbers for men!

 

A little correction: Women are XX. Men are XY. Sperm are either X or Y. All eggs are X.

 

Ancestry.com has become quite popular in the last few years w.r.t such tests. Unsure if we have something similar in India.

Certain southern Indian states have people marrying someone with last name. The last name will be mostly caste name. Within the caste they have sub-castes. They cannot marry within the same sub-castes.

 

Why it has to be father's or husband's name? - It was a man-made rule in a patriarchal society. We still follow it.
Recent times have hyphenated surnames emerging or both parents name's first letters as initials of the kid's name.

 

A certain movement in 1970's caused people from several Indian states, specifically two northern states to drop using surnames. The movement focused on eradicating corruption by demolishing the use of caste names as surnames to distinguish between upper and lower classes.
Double names were given based on what age the person was at.
Babu - for little ones
Kumar/Kumari - for ones who are yet to get married
Devi/Raj/Rani/Raja - After marriage
Taking on family names - After men take over family responsibilities

Some southern states used the words master/baby for little boys/girls for a time period.

 

Thanks for correcting me. I think it was typo.