Its about brahmins

'Gotra' may be defined as a concept of patrilineal classification and identification of various families of a caste.

Gotra could be one of the ancient 'Aryanized' Indian traditions. The gotra classification came into existence probably sometime during the Vedic period. The gotra system might have started originally among Brahmins as a system of classification and identification of various families and indicating common descent from a 'rishi'. Rishi means a sage. The Vedas were revealed to them and the respective hymns stand in their names.

But it seems that during the course of time, many castes in Hindu society have adopted the concept of classification and identification (i.e., gotra) of families among themselves.

So the term 'gotra' is applied to that grouping stemming from a rishi as his descendants, or considering that rishi as a priest (or guru) of a clan. Since the word 'gotra' also connotes the association originating from a rishi as a priest (or guru) of a clan, a few other castes also happen to share some of the gotras of Brahmins.

Gotras

Seven Rishis (saptarshi) are recognized as the mind born sons of the creator BrahmaThe ’Shatapatha Brahmana’ gives their names as:

• Atri
• Bharadwaja
• Gautam
• Jamadagni
• Kashyapa
• Vasishtha
• Vishwamitra

Out of these seven rishis, Viaswamitra was basically a Kshatriya king, who chose and rose to become an ascetic rishi.

Over the years the number of gotras increased due to: (1) Descendants of original rishi also started new family lineage or new gotras, (2) By inter marriage with other sub-groups of the same caste, and (3) Inspired by another rishi whose name they bear as their own Gotra.

PRAVARA  is a set of the greatest rishis who belonged to the gotra. Usually these are the founding fathers (and in a few cases, founding mothers) of the gotra. In vedic ritual, the importance of the pravara appears to be in its use by the ritualist for extolling his ancestry and proclaiming, "as a descendant of worthy ancestors, I am a fit and proper person to do the act I am performing."

Some authors claim that the rishi  Jamadagni was a descendant of rishi Bhrigu while the rishis Gautam and Bharadwaja were the descendants of rishi Angirasa

The ‘Pravara’ identifies the association of a person with two, three (or sometimes five) of the above-mentioned rishis. It also signifies the ‘Sutras’ contributed to different Vedas by these rishis.

Marriages and gotras

The desire of the ancient Aryans to avoid cosanguineous marriages [marriages between blood relatives] resulted in the establishment of strict rules determining which lineages could or could not intermarry. This thinking is in tune with the modern day genetic paradigms of hybrid vigor. The concept of gotra-pravara made such systems of exogamy [marriage outside of a specific group especially as required by custom or law] eminently feasible. The gotra is therefore frequently used as an exogamous unit to determine marital compatibility. Marriage is not recommended between two individuals of the same major gotra [ i.e. the two individuals should not be able to trace their patrilineal ancestry to one and the same of the 7 primal rishis listed above ]. Furthermore, marriage is prohibited between two persons who share even one pravara rishi.

The significant exceptions to this rule are in the cases of the descendents of Bhrigu and {{Angirasa]]. In the cases of the Bhrigu  and angirasas, marriage is prohibited only when a majority of the pravara rishis are common to the two individuals. Thus many of the ganas of the Bhrigus and Angirasas are considered individual exogamous units. Overall, there are 18 exogamous groups within Brahmin community.

The reasoning determining this marital incompatibility might be that marrying within one's gotra would be akin to marrying one's sister and would be akin to incest. However, in south India, this definition of incestuousness took some peculiar forms. In some communities, where the gotras passed from father to children, marriages were allowed between uncle and niece. A much more common characteristic of Daivajna community is a marriage between cross-cousins(between children of brother and sister). Thus, a man may marry his mother's brother's daughter or his father's sister's daughter but could not marry his father's brother's daughter. A father's brother's daughter is treated as a sister. Even this cross-cousin marriage is frowned upon by the rest of the Hindu society.

List of gotras

As described earlier, the word 'gotra' also connotes the association originating from a rishi as a priest (or guru) of a clan, a few other castes also happen to share some of the gotras of Brahmins.

The ten Gotras of the Daivajnas and their respective Pravaras:

Gotras  1. Bharadwaj 2. Kousika 3. Vatsa 4. Koundinya 5. Kashyapa 6. Vasishta 7. Jamadagni 8. Vishwamithra 9. Gautama 10.Atri

Pravaras : Angirasa, Bhaarhaspathya, Bharadwaaja : Viswaamithra, Akhamarshana, Kousika : Bhaargava, Chyavana, Aapthavaana, Ourva, Jaamadagnya : Vaasishta, Maithraavaruna, Koundinya : Kaasyapa, Aavatsaara, Naidruva : Vaasishta Indrapradama, Aabharaswath : Bhaargava, Chyavana, Aapthavaanam, Ourva, Jaamadagnya : Viswaamithra, Devaraatha, Oudala : Amgirasa, Aayasya, Gouthama : Aathreya, Archanaanasa, Syavaaswa

The following gotras are also found in Daivajnas

Gotras                            Pravara

Sanaga                                    Manu,Vishwadeva,Sanaga

Sanatana                                 Sanatana,Vishnu,Vamadeva

Ahabhuna                               Ahabhuna,Twashta,Vishwarupa

Pratna                                     Shilpi,Vastuka,Ruchidatta,Pratna,Sanabhasa

Suparna                                  Suparna,Sark,Vishwadnya   

YOGESHWARA YAJNAVALKYA

The name of Yajnavalkya of Mithila stands distinguished both in the Srutis and in the Smritis. Yajnavalkya is especially known for his unsurpassed spiritual wisdom and power. The seer of a Veda Samhita from Bhagavan Surya, the revealer of Brahma Jnana to Janaka, Maitreyi and others, Yajnavalkya hails supreme among sages of sacred memory. As to his obtaining the Shukla Yajurveda Samhita from Bhagavan Surya, there is the following history.
Yajnavalkya was the son of the sister of Mahamuni Vaishampayana, the Vedacharya of the Taittiriya section. He was studying the Taittiriya Samhita from Vaishampayana who was also his Guru. Vaishampayana had many other disciples too and they all were students of the Taittiriya Shakha.
Once all the Rishis decided to form an association near the Meru mountain and made a rule that any Rishi who absented himself at the appointed hour should incur the sin of Brahmahatya (the sin of killing a Brahmin) for seven days. On that appointed day fell the Sraddha ceremony of Vaishampayana’s father. Vaishampayana thought, "Somehow I have to perform my father’s ceremony. If the sin of Brahmahatya comes to me, my disciples will observe the expiatory penance therefor". So Vaishampayana did not attend the meeting of the Rishis. And accordingly he incurred the sin of Brahmahatya.
Then Vaishampayana said to his disciples, "Now I have to expiate this great sin of Brahmahatya. Therefore, you all will observe, for my sake, an expiatory penance for seven days".
At once Yajnavalkya stood up and said, "O Guru! All these are poor-spirited young students. They will not be able to undergo such a hard penance. So, instead of all, I myself alone shall observe it in the manner in which nobody else can". Vaishampayana told Yajnavalkya not to undertake it alone. But Yajnavalkya persisted. The preceptor was offended at this audacious attitude of the disciple and said, "O proud one, you are very conceited. You get away from me. Enough of you who is disposed to despise wise Brahmins. Give back to me immediately whatever you have learnt from me".
Upon the order of the Guru, Yajnavalkya, the son of Devarata, vomited out the collection of the Yajus in the form of food. The other disciples ate that food taking the form of the Tittiri birds, because they were very eager to receive the same. They then had the direct revelation of those Yajurveda collections. As the Tittiri birds ate this Veda, it is thenceforth called the Taittiriya Yajurveda. It is also known as Krishna (black) Yajurveda on account of its being vomited substance.
Then Yajnavalkya determined not to have any human Guru thereafter. Thus he began to propitiate the Sun-God, Surya. Yajnavalkya worshipped and extolled the Sun, the master of the Vedas, for the purpose of acquiring the fresh Vedic portions not known to his preceptor, Vaishampayana.
Yajnavalkya said, "Prostration to the glorious Aditya, who in the form of the Atman, abides in all beings. I bow to Him who surrounds all like Akasa, who is one and not separated or distanced by limiting conditions. O Great God, O Creator, I contemplate upon that glowing sphere which lights and warms the whole world! O God who burns all miseries wrought by unrighteous activities, who burns ignorance which is the seed of activity! O Lord, I worship Thy lotus-like feet praised and worshipped by the rulers of the three worlds. Give me those portions of the Veda which are not known to others".
The Sun-God, the glorious Lord Hari, pleased with Yajnavalkya’s penance, assumed the form of a horse and taught the sage such fresh portions of the Yajurveda as were not known to any other. This portion of the Yajurveda goes by the name of Shukla Yajurveda. It is also known as Vajasaneya Yajurveda, because it was evolved in great rapidity by Surya in the form of a horse through his manes. Yajnavalkya divided this Vajasaneya Yajurveda again into fifteen branches, each branch comprising hundreds of Yajus Mantras. Kanva, Madhyandina and others learnt those branches.
Yajnavalkya married two wives. One was Maitreyi and the other Katyayani. Of the two, Maitreyi was a Brahmavadini. When Yajnavalkya wished to divide his property between the two wives before starting for the fourth Ashrama of his life, Maitreyi asked whether she could become immortal through wealth. Yajnavalkya replied that there was no hope of immortality through wealth and that she would only become one among the many who were well-to-do on earth. On hearing this, Maitreyi requested Yajnavalkya to teach her what he considered as the best. Then Yajnavalkya elaborately described to her the sole greatness of the Absolute Self, the nature of Its existence, the way of attaining infinite knowledge and immortality, etc. This immortal conversation between Yajnavalkya and Maitreyi is recorded in the Brihadaranyaka Upanishad. The central theme of the discourse is this: "All things are dear, not for their sake, but for the sake of the Self. This Self alone exists everywhere. It cannot be understood or known, for It alone is the Understander and the Knower. Its nature cannot be said to be positively as such. It is realised through endless denials as ‘not this, not this’. The Self is self-luminous, indestructible, unthinkable".
The other wife Katyayani, the daughter of Bharadhwaja, was of common intelligence, and through her Yajnavalkya had three sons—Chandrakanta, Mahamegha and Vijaya.
Yajnavalkya, though a great Brahmajnani, was a great Karmakandi too. He caused many Yajnas to be performed and himself became the Acharya of those great Yajnas. He was a celebrated Srotriya and a Brahma-nishtha Guru. Once King Janaka of Videha wanted to know from which real Brahmanishtha to receive Brahma Vidya. In order to find out who was the real Brahma-nishtha, Janaka performed a huge Bahu-dakshina sacrifice to which all the Rishis from far and wide were invited. And he offered one thousand cows with their calves, all their horns being decked with enormous gold. Then he proclaimed to the assembled ones, "Whosoever is the best Brahmana amongst you may drive these cows home". None dared to get up and take away the cows as they were afraid of censure by the others. But Yajnavalkya stood up and asked his disciple Samasravas to drive the cows home.
The other Brahmanas got angry at this and said to one another, "How can he declare himself to be the best among us?". Thereupon several Rishis challenged Yajnavalkya with many questions on transcendental matters to all of which Yajnavalkya gave prompt reply. There was a great debate in which Yajnavalkya won over all the others. Janaka was convinced that Yajnavalkya was the best Brahma-nishtha and received Brahma Vidya from him thereafter.
The third and the fourth chapters of the Brihadaranyaka Upanishad abound with the great philosophical teachings of Yajnavalkya. Yajnavalkya was also the author of the famous Yajnavalkya Smriti. His other works are Yajnavalkya Shakha, Pratijna Sutra, Satapatha Brahmana, and Yoga-Yajnavalkya.
At the sacrifice of Janaka, there was an exchange of words between Yajnavalkya and Vaishampayana. But on hearing that Yajnavalkya had obtained a fresh Veda from the Sun-God, Vaishampayana was much pleased and he requested Yajnavalkya to teach that Veda to his own disciples also. Yajnavalkya consented and taught his Veda to the disciples of Vaishampayana.
In the end, Yajnavalkya took Vidvat Sannyasa (renunciation after the attainment of the knowledge of Brahman) and retired to the forest.
Yajnavalkya was one of the greatest sages ever known. We find him arguing with and overcoming even his teacher Uddalaka at the court of Janaka. His precepts as contained in the Upanishads stand foremost as the crest-jewel of the highest teachings on Brahma Vidya.