The debate has raged during the past decade. The Aryan invasion theory stated that the Aryans entered a civilizaed India , where the Dravidian and other people lived in wall cities. The AIT made it clear, as indicated by the Vedic literature that the Aryans were clearly nomads who attacked the cities of North India . Since there was nothing in the Vedic literature which idetified them as civilized,the Indus Valley Civilization was credited to the Dravidian people .
In the 1990's population genetics became popular. At first the science was used to identify connections in a positive fashion. As more and more research was done it was recognize that many Eurasians carried African genes.
Although history and archaeology illustrated that Africans had migrated to Eurasia since 3500 BC, the geneticist began to refine their methods to differentiate between Africans and Europeans who carried the same gene by refining their methods and giving the same gene held by different groups, diferent names.
Based on the monogentic theory that man originated in Africa, geneticist accepted the fact that anatomically modern humans (amh) originated in Africa between 200-100,000 years ago (kya). Next, the geneticist claimed that amh left Africa 60kya.
On the surface this was a neutral conclusion, but in reality it had deep implications for anthropology. First of all radio-carbon dates and skeletal remains make it clear that their is no single African Black population. As mankind developed in Africa different people appeared at different types which were all similar in color but had selected features which indicated differences.
Thus we have:
1) The Australian people have curly, wavy or straight hair and abundant body hair and sloping brows and with prominent ridges.
2) The next group were the San who have curly hair , the brows were vertical and without prominent eyebrow ridges . The San were of medium build.
3)The next group were the Pgymy have curly hair , the brows were vertical and without prominent eyebrow ridges . The San were short in stature.
4) Finally we have the African-Melanesian- Oceanic type who have curly hair , the brows were vertical and without prominent eyebrow ridges . The African-Oceanic type is tall in stature.
These types of Negroes are supported by craniometric and skeletal remains recovered from archaeological excavations. This evidence supports multiple migrations.
Because the archaeological evidence supports Africans existing in Europe and Eurasia generally it explained why Eurasiatic people carry African genes.They carry African genes because they were carried to Eurasia in recent times.
Genetics, like the other sciences is Eurocentric. So these researchers used the genetic data that Eurasians carried African genes to imply that since the out of Africa (OOA) event occured only once in 60kya, any genes carried by Eurasians that are derived from African genes must be the result of a back migration ( i.e., Europeans took the African genes they acquired after 60kya back to Africa ).
The main problem with this theory was that it is not supported by the skeletal remains and archaeology which show that Blacks entered the areas at different times since 60kya. Although the genetics have no archaeological and skeletal evidence to support the presence of European and mongoloid people in this or that region, they use statistical methods to claim that Eurasians possessed this or that gene earlier than the same gene in Africa.
Now Eurocentrist can claim that yea, Blacks were in Eurasia, but these Blacks are all derived from the OOA event--not recent migrations.
There was only one problem with this idea:the Dravidians. The Dravidians have long been recognized as Negroes by anthropologist. They shared blood type and cultural features.
In 1999 Kivisild et al, wrote a paper claiming that Dravidians carried the M1 haplogroup. This was evidence that the Dravidians must be related to Africans because hg M1 is primarially found in Africa, especially Ethiopia .
Later Hindu nationalists took over the India government. They began to fund researchers and the 1999 Kivisild article was ignored, and geneticists began to claim that hg M1 did not exist in India, eventhough we have the Kivisild et al 1999 study.
Today the Hindu nationalist claim that Dravidians originated in India and since they share genes with the Indo-Aryan speakers they too must be native to India. Their reasoning continues, that if the Indo-Aryan people were in India since time memorial and they live in North India, while the Dravidians live in South India , it was the Indo-Aryan people who founded the Indus Valley civilization and probably spread the Indo-European languages to Europe. The myth that Indo-Aryan people have always lived in India--provided the Hindu nationalists with the fuel to claim that the Aryan invasion was a myth created by the European colonists.
This meant that the only way the Indo-Aryans can claim an insitu origination is based on genetic evidence. Genetic research is being used to revise India history by erasing Dravidians from Indian history and replacing them with Indo-Aryan speakers.
What the Hindu nationalists did not know is that the archaeology, linguistics and the 1999 Kivisild et al article point to a recent (c. 3000-2500) migration of Dravidians from Africa to India--not an insitu development of Dravidian speakers in India. The Hindu nationalist must support genetic research to provide them with a prominent role.
In summary Indo-Aryans attack the Aryan Invasion theory (AIT) because it makes them recent immigrants to India. To deny the AIT "whites" out Dravidians from India history. The attacks on AIT by Hindu Nationalists is made to give Indo-Aryan people a history they do not deserve.