Aryan may come from India and Iran, but the term Aryan does not equate to Proto-Indo-European.
Aryan itself might be a mixture of several different groups before it is linguistically formed.
These are not irreconcilable.
Aryan was a language category, one which was used to describe a third- or fourth-generation derivative of Proto-Indo-European. As we all know, PIE itself was a re-discovered language. We think it was spoken; nobody knows for sure. We even derived the language by back-extrapolation from later derivatives, which we think were derivatives.
Neither Proto-Indo-European nor Aryan was a racial or ethnic category. Both PIE and Indo-Aryan, not Aryan, were originally language/ linguistic categories; today's practice in India is to distinguish between those languages derived from Indo-Aryan and those derived from proto-Dravidian, including Kol/Mundari, and to call them Aryan and Dravidian.
Discussions on Aryan and Dravidian are difficult and sensitive in the extreme, for both a European and a South Asian reason.
The European reason was the deranged racism which culminated in Hitler's anti-Jewish pogroms. This had a very, very long history, going back to the persecutions of the Jews from the earliest times in Europe, far less so in Asia. However, the impetus this anti-Semitic persecution got in the 18th and 19th centuries, and to some extent in the 20th century, was the application of totally distorted and misunderstood genetic theories based on a master-race. It was considered that tall, fair, blue-eyed, blonde, white folks were the master race, the Aryans, a hilarious displacement of a name across centuries and across thousands of kilometres.
This theory was used to justify the elimination of other inferior races, such as the Jews; ironically, proportioinately less Jews were murdered than Romani, the Gypsies of Europe, who had a far greater right than the tall, fair, and all the rest of it Caucasians to call themselves Aryan.
It may be objected that technically, the Romani were not necessarily Aryan in the south Asian sense; Aryan was a social category among the immigrants into South Asia, consisting of the king, the nobility, the warriors in general, and the priests; others, even of the same tribe, even marrying into these other families, and living in the same habitations, were not. But in Iran, the people in general considered themselves the Aryan people, not just a ruling class and its adjuncts. Considering that the Gypsies were descendants of the prisoners taken in India by Mahmud of Ghazni and subsequent invaders (they appear in Italy from Egypt, and the earliest traces are after the 11th century), and that they had a number of years in the Middle East, this fits very well. Incidentally the Roma in France call themselves Manush, other groups call themselves Dom; very familiar to South Asian readers.
The South Asian reason is far more dangerous. It has to do with Brahminism and the caste structure. the Brahmins have assiduously fanned the flames of the myth that there were ethnic distinctions between the early/original inhabitants of south Asia and the later migrants, and that these distinctions show up in the facial and physiognomical differences between different peoples. This is utterly false and has been conclusively disproved by scientific genetic study, and it is time that the use of Aryan as a code word for purity of race or descent was eliminated altogether.
Part of this myth-building, which took place over nearly two thousand years, leading to its being rooted in the minds and the sensitivities of most south Asians, was the further myth of a certain cachet of immigration; migrants were the great ones, the pure ones, 'sent' or summoned to purify either religious practices, or the race. There was a complete and inhuman domination of south India by the 2% of the population that this single caste represented, marked by practices that don't really warrant re-telling. The direct result was a deep-seated animosity that will take years of democratic living together as equals to cleanse and remove.
A few points in conclusion:
- The Aryans were not a race, and are not distinct from the rest of the population in racial or in genetic terms;
- As has just been said in an immediately earlier post, Aryans were thoroughly mixed in ethnic terms. We have indirect evidence; their kinfolk among the other Aryans, the ones who went to Iran or stayed back on the steppes, the Scythians, spoke east Iranian and were by all reports thoroughly mixed. They were far from exclusive ethnic stock, and were mixed races occupying the steppe lands from the Aral Sea to near the European river systems;
- The term was used to specify a certain class among immigrant tribes, and should correctly be used only in that historical context in social matters;
- It was, and is also used to distinguish many south Asian languages from the north of the sub-continent, from the languages in the south of the sub-continent. The southern languages are Tamizh, Telugu, Kannada and Malayalam. In addition, there are several other smaller language groups belonging to the Dravidian, including, it is thought, the Kol-Mundari group.
- There was a spread of Indo-Aryan languages throughout the three northern and western river basins, the Indus, the Ganges and the Narmada. This was accompanied by the thorough and complete assimilation of the immigrating people into the vastly greater indigenous population that they found already in residence.
- There were migrations from North to South, but migrations of individuals only and not tribes; perhaps, at best, several families at a time may have travelled together.
- The Brahmins originated this theory of re-population of the south by some select social leaders, and managed to get others to subscribe to it also; you will therefore find some others also insistent on a migrant status, and its wholly mythical aura of exclusivity;
- Brahmin exclusivity was a myth, assiduously pushed by the hoped-for beneficiary.
Regarding the ethnic and racial relations between different sets of immigrants sweeping in and out of the sub-continent, it is emerging slowly, although much more work is needed to validate this hypothesis, that
- There was an existing population of very significant size from the Palaeolithic Age onwards;
- Languages spoken by this population are unknown;
- The Dravidian-speaking immigrants came in from south-east Asia and the Indonesian archipelago in pre-historic times and settled across the whole land-mass of India, including in parts of Baluchistan and Seistan;
- They have left traces of their presence behind, in the form of the Brahui language;
- Their relationship to the IVC is unproven at this point of time, but some very exciting work was done in Chennai (ironically, by non-Tamilians, by Bengalis, actually) on mathematical pattern-matching of the IVC symbols with letters and patterns used by different Indian languages, when the electrifying discovery was made that the closest match was with Tamizh;
- These immigrants contributed their language to the existing population: if Kol-Mundari are Dravidian languages, then their penetration was right across the top of the peninsula, as Kol-Mundari speech is found very far east on the sub-continent;
- The domination of the Dravidian languages diminished with the coming of the Indo-Aryan languages, and remained only in the shape of the Kol-Mundari spoken by certain shy forest and hill-dwelling segments of society in North India; they are extensively distributed over south India, from Telugu and Kannada in the north, to Tamizh and its recent descendant, Malayalam;
- The genetic pattern remained undisturbed, as it had been undisturbed when Dravidian came into the country several centuries earlier;
- These languages are important but those who speak them cannot be described as belonging to this or to that ethnic origin.
I hope this is helpful.