However, this origin has not been proven, and many runic origin theories have been advocated.

Appropriate origin theories were created to justify their lowly rank in the new social order.

These origin theories typically involve contact with Old World societies.

Besides, Nancy and I had come up with another origin theory that roused our protective instincts.

He advocates the oriental origin theory for the Etruscans:

The single origin theory holds that domestication occurred once, after which all breeds arose through selective breeding.

A more widely accepted origin theory is the Epsom Derby horse race.

Another origin theory is that the town was named after the Shenandoah Valley in Virginia.

Other linguists disagree with the Chinese origin theory because there is no conclusive evidence that the word originated from China.

The factors responsible for the acceptance of tribal origin theories are as under: