As I have mentioned before I am skeptical about Coastal Migration Theory. This theory proposes a set of Homo Sapiens after leaving Africa rapidly colonized South Asia, SE Asia and Australia moving rapidly along the coastal regions. Y-Haplogroup C is generally considered as the marker of that coastal migration.
One of the C's in India belong to subclade C5 is distributed across India. However, there are C* in South India that might be the legacy of coastal migration. I compared the tribes and castes that carry this lineage and I observed a strange pattern in its association with other haplogroups.
I make the following assumption before coming to my conclusions.
If a haplogroup is observed in more than one endogamous tribe/caste then its uncharacteristic presence in any group cannot be explained with genetic drift or bottleneck or founder effect.
That haplogroup in the below table is R1a1. As far as I can see C* is observed in conjunction with R1a1.
Tribe/Caste: Observed Haplogroups - Region
Koya Dora/Konda Reddy - F, H, O2a - South - East
Kurumba - F, H, R2, L1 - South - West
Kamar - F, H, L1, O2a - South - East
Yerava - F, H, C*, R1a1 - South - West
Koraga - H, R2, YAP - South - West
Toda - L1, J2a, R1a1, C* - South - West
Pallar - F, H, R1a1, C*, J2b- South - West
Based on the above data I propose the following pre-neolithic migrations.
1. Africa-Middle East-South Asia : F, H
2. ? -> East India : O2a
3. Central Asia - south west coastal India : R1a1, C* (one of the first migrations of R1a1)
4. ? -> south-west India: L1
5. ? -> south-west India: R2
I don't see the possibility of coastal migration with this scenario.
1. Cordaux et al. 2004
2. Sengupta et al. 2006