[Advaita-l] Aryan Invasion-What Advaitin Scholars say?

[Suresh]

Dear Friends,

The thread on varnashrama dharma impelled me to start this one. I want to keep it separate, because it doesn't specifically concern varnashrama, but rather factors giving birth to varnashrama.

I've been brought up to believe in the Aryan invasion theory, because it makes sense as to how varnashrama could've developed. It's quite easy to believe that fair-skinned Aryans created this system to keep the different races separate from each other. Also in bhagavat gita 1.40-1.43, we see hints on what happens if castes mingle. 

More importantly, we also see in modern India, most people who appear to be a mix of black and white, rather than pure white or black. This also indicates that varna sankara must've taken place between fair-skinned Aryans and dark-skinned Dravidians, which is why Indians happen to be a mixture of both. 

Based on all this, would it be reasonable to conclude that caste system was never properly followed in India? What do advaitin scholars say about this? Caste system was in existence, even when the gita was spoken. So is it possible that the Aryan Invasion Theory could be true, and this in turn gave birth to varnashrama? 

Without AI (and consequently the presence of different races in India), there would've been no reason to fear varna sankara; hence my query.

Warmly,
Suresh