Book excerpt: Scientists discover Y-DNA haplogroups O2a and mt-DNA haplogroup M4a in the Rakhigarhi ancient DNA. These haplogroups are associated with the speakers of Austro-Asiatic languages such as Mundari, Santali and Khasi. These haplogroups and related languages are also present in Southeast Asia. In India, speakers of these languages are currently found mostly in Central and East India. Even though a prominent philologist of Harvard University, Mr. Michael Witzel, has argued the case for a language close to Munda (which he calls para-Mundari) being one of the languages of the erstwhile Indus Valley, a finding of this nature will come as a surprise to most others. So if the genetics do find haplogroups O and M4a in Rakhigarhi, some of our current understanding of Indian history may have to be revised. Tony Joseph in The Hindu, December 23, 2017