Endogamous group is a community in which the members generally marry within the group. The caste in India and the tribes in many of the cultural regions of the world form endogamous groups.
In multi-ethnic societies with many small populations of distinct ethnicities in proximity to each other, the endogamous groups are generally combinations of similar ethnicities, leading to the social conception of "race".
The Knanites in Kerala, India are a perfect example of this, as are the Ashkenazi Jews. [1].
Knanites are believed to be migrated from the Middle East to India in AD345. They have been marrying only amongst themselves ever since.
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