Astrology: not when but where

I just had an epiphany.

What if are misconstruing the true meaning of astrological traits? By this, i mean what if the zodiac sign's don't represent the time you were born, but the characteristic traits of your ancestors?

for instance :

Grecian : Taurus the bull

Native american : Cancer the crab/turtle

Asian : Draco the dragon

just a few examples and classically they seem to fit. Also if we all did not originate from here, is this a clue to the different races origins?