Kashyapa is the father of Garuda,
the heavenly eagle who acts as the animal "vehicle" for the deity
Vishnu, and the chief of the Prajapatis (a class of semi celestial creatures)
in Hindu mythology.
Gautama, Bharadvaja, Vasishtha,
Bhrgu, Atri, and Vishvamitra are the other Seven Sages whose names signify
exogamous clan "lineages" (gotra).
All brahmins are said to be
descended from these seven sages, with each family adopting their progenitor's
name as their gotra name.
Gotras are still essential in
current times, since marriage inside a gotra is prohibited.
The new bride takes her husband's
gotra as part of her new identity after their marriage.
Prohibitions against marriage may
also be found here.
You may also want to read more about Hinduism here.
Be sure to check out my writings on religion here.