This is very interesting, I always thought of Australian natives as having been a part of an out-migration of similar populations (remnants of which still exist

This is very interesting, I always thought of Australian natives as having been a part of an out-migration of similar populations (remnants of which still exist, e.g., Andamanese in India, small populations in Thailand, Malaysia, and Philippines, etc...) from South/South-East Asia -- with intermarriage between further migrations (Indo-European speakers, Austronesians, etc...) and these remnant populations leading to form the different ethnic groups along the route of migration. I wonder if another possible explanation for the Dravidic SNPs is due to intermarriage with Indonesian population -- themselves probably bearing some Dravidic DNA due to India's influence on Indonesia at one time -- that traveled to Northern Australia from the late middle ages until early 20th century for fishing and trade purposes.