1) I hate to say it but often lower castes have dark skin and african features. You will also find most of the brightest students in a University are brahmins - the highest caste - just ask your friends their caste and correlate with their intelligence. The caste system is racist. You cannot change your caste. Period. You were born with it. It is interesting but sad. Forced hereditary occupations lead to differences in appearance and even IQ across thousands of years. Low castes clean toilets - high castes are priests in temples (translation: the intellectual leaders today).
2) The caste system is very prevalent. It also leads to corruption similarly as Rick Warren found tribalism was the cause of corruption in Africa.
3) How many white-black mixed marriages do you see in America? Not many. Most kids up for adoption are biracial black-white. The prejudices remain over here in the USA - at least in relationships. Read the chapter on preferences in interracial dating in the book Freakonomics.
2) The caste system is very prevalent. It also leads to corruption similarly as Rick Warren found tribalism was the cause of corruption in Africa.
3) How many white-black mixed marriages do you see in America? Not many. Most kids up for adoption are biracial black-white. The prejudices remain over here in the USA - at least in relationships. Read the chapter on preferences in interracial dating in the book Freakonomics.