A Brahmin should eat on the fifth quarter of the day, Never rich food, Live near the banks of Rivers, Eat vegetables,fruits and Roots grown in a property which is not owned by anyone. He should know all subjects but practice only spirituality.
Latest Tsunami after Mahabharata War resulted in Sage Agastya bringing 71 Families from there and settling them in the present Karnataka and Tamil Nadu. These settlers in Tamil Nadu ruled the border areas of Karnataka, Coimbatore, Dharma puri, Salem and Erode areas as Velirs, small kingdoms under the three great kingdoms of Chera, Chola and Pandya.I have written on this. Another migration seems to have been there before Ramayana period and this seems to have been led by Bhargava Rama, popularly known as Parashurama.
And Brahmins created(?) the Vedas to control the social groups. Even among Brahmins there are many who think that the Vedas are not to be shared with the other communities. Wrong. Veda comes from the word 'Vid' meaning to Know or Knowledge.. It is not the preserve of one community. That the Vedas were made by Brahmins is equally wrong.. Many of the great Rishis and those who contributed Veda Sukthas were not Brahmins. Some of them are.
And over a period of years Brahmins have started using their professions as their surnames ,as against the Hindu practice of using Sharma as their surname and for indentification their Pravara/Abhivadan Mantra. So when one has a surname like Upadhyaya it merely denotes the profession and not a caste. To find it one has to check the Pravara.
Yet people vilify Brahmins of practicing Untouchability. Despite my vigorous checking, I am yet to find a Brahmin being accused of practicing Untouchability and charged under the Law! Other Communities have been named. Then the stock answer, is that Brahmins consider as Theettu, and wash themselves or the place where they( SC /ST) sat. This is a matter of.personal habit, though some smritis suggest this and they are not being followed by every one,