Because there is no Aryan culture outside India and there is no point at all in Aryan literature where they mention their so called central asian lebensraum. Not even once. I'm not saying that no one ever came into India in ancient times.
What is "Aryan culture"? Indians certainly were not the only people who called themselves as Aryas.
And what is "Aryan literature"? Are we talking about only Vedic Aryan literature, or also that of Iranian peoples, who also called themselves Aryans? It is true that the Vedic Aryans do not mention Central Asia anywhere, because they were most likely indigenous people (or mostly indigenous) of NW India who gradually adopted Aryan culture. Moreover, the Vedas were probably composed at a time when the Vedic Aryans regarded themselves as the "natives" of Sapta-Sindhu, even if they originally came from outside.
Are you sure? Harappans predate 2nd milennium, Vedas and Farming predate Harappans. Anyway my point is, when there are 2 peer languages in adjacent areas with no conflict whatsoever, expansion is possible only in a relative vaccum. South was boxed between north and thee sea. Only the north had a chance to scout.
The Harappans should not be conflated with "Indic" civilization, which emerged much later. Most of India during this time-frame was not yet home to civilization, as the IVC only covered a small portion of the Indian subcontinent. The eastern Indo-Gangetic plain, Central India, Deccan, and South India had no civilization whatsoever worth talking about. Urban civilization even mildly comparable to that of the Harappans would not exist in other parts of India until the mid-1st millennium B.C.E., with the rise of Magadha and other mahajanapadas. In South India and the Deccan, urban civilization would not emerge until even later, in the early centuries C.E.
So this again brings us to my original question, which has still not yet been satisfactorily answered: if NW India was the PIE urheimat, why didn't IE languages spread to South India, which was far closer to NW India than Britain and France. There was certainly no advanced civilization in South India at this time, which would somehow make it immune to adopting Aryan languages.
I don't know of any evidence indicating to other competing civilization to have existed in the proposed Aryan urheimats of Central Asia or Eurasia. A competing civilization that could either refine a language as marvelous as Sanskrit or as original as the parent of Sanskrit. Should I expect that from the roaming nomads of central asian pastures?
Central Asia was home to the BMAC which was a sophisticated urban civilization like the IVC. Moreover, there also existed great pre-Aryan civilizations in southwest Iran, namely at Elam (modern Khuzestan) and Anshan (modern Fars). The original homeland of the Persians was in southern Central Asia and Afghanistan. This region was known as Ariana to the Greeks, and its inhabitants as Arianoi (Aryans). The Persians did not fully establish themselves on the Iranian plateau until the first millennium B.C.E., by which time the Aryanization of the ancient Elamite and Anshanite populations of southwest Iran was well under way.
As for Sanskrit, it didn't even exist in the time frame that we are discussing. It was not Sanskrit which spread across Eurasia, but common IE linguistic elements which gave rise to a plethora of different regional languages. The emergence of Sanskrit was a by-product of the resurgence of civilization in NW India in the mid-1st millennium B.C.E., long after the time period in question.
Obivously if the Indians spread as ambassadors of our civilization, there wiill be people from influenced areas who will come to India. When the west completely influences and overawes the third world today, don't the people want to go see the west at least for once. Some would dream of settling there.
In future if someone saw minor Indian genes in US population and claimed US to have been civilied by India
.. well ..
So, where are the great civilizational traces left behind by the outward migrations of the Vedic Aryans in Britain and Scandinavia? I cannot find them.
Superstratum means the incoming and dominating group leave its imprint on the host population and its language. That is exactly what I mean by the influence of the outgoing Aryans of India.
A superstratum case is one where an incoming and dominating group assimilates into the larger population over which they rule, and adopts their language. In the process, they leave an influence on the native language, which is called the superstratum; the native language itself, however, remains intact. The substratum case is the opposite scenario, where the language of an intruding group is successfully imposed on the larger population, but in the process acquires and retains some elements of the native language. The native influence on the new language is called the substratum.
The IE expansions were characterized by the substratum case, not the superstratum. The entire nature of the languages spanning between Western Europe and North India changed and took on many common characteristics, enabling later linguistics to classify them as belonging to one huge language family. Of course, these IE languages also retained elements of their pre-Aryan linguistic heritage, as can be seen by the numerous words of Dravidian or Austro-Asiatic origin in Sanskrit. On the other hand, an example of the superstratum case can be seen with the Sanskritic influence on Dravidian and Malay languages. There are numerous Malay words which are of Sanskrit origin, such as "mandala", "bhumiputra", and even "Malaya" itself. But this influence is only superficial, as the mass of the population continues to speak Malay languages, and not an IE one like Sanskrit. The same is true for the Sanskrit superstratum in Dravidian languages.
The mixing would start soon after the Ice Age ends and people from coastal areas are thrown deep into mainlands. Nobody is waiting for a timetable of 2nd milennium B.C.E.
There is no evidence of IE language in South India before the Mauryan expansion into the region. Subsequently, regional states in the region which emerged in the post-Mauryan period, including the Satavahanas and Pallavas, used IE languages (Sanskrit and Prakrits) as the court and literary languages. However, these languages were never spoken by the masses as a whole, who continued to speak Dravidian languages. Eventually, the native languages like Tamil, Telugu, and Kannada displaced Prakrits and then Sanskrit as the major court and literary languages, and were patronized by states and elites. But by this time, of course, there was already a significant Sanskrit superstratum in these languages.
