An informative post!
I agree with your view that australoasian groups were the earliest in south India.
Since you are better read in this subject can you inform me how did they come from Africa to India. I suspect it was not via middle east.
Could this not be a legacy of the sea faring tamils and an occurence of a much later period?
Dear Subbudu Sir:
In my view of the Southern Route of Human Migration from Africa towards Australia about 100.000 years ago, India and the Austroasians come along.
Therefore, it is conceivable that the Original Indians who settled in South India also spoke a form of the Austroasian languages..