Genetics
A 2010 study by the Anthropological Survey of India and the Texas-based Southwest Foundation for Biomedical Research identified seven genomes from 26 isolated "relic tribes" (sic) from the Indian mainland, Baiga being one of them, which share "two synonymous polymorphisms with the M42 haplogroup, which is specific to Australian Aborigines." These were specific mtDNA mutations that are shared exclusively by Australian aborigines and these Indian tribes, and no other known human groupings.
Read more about this topic: Baiga Tribe