Aryan Invasion Theory has been proved to be a myth and as a wrong theory long back. But let me explain in detail the actual history and dirty politics behind this theory. Note that this theory was used as a basis by Hitler to advocate his theory of the supremacy of the Aryan race and to mindlessly kill whom he claimed to be non-aryans!
Let us first see what the Aryan Invasion Theory says.
It calls the race which belonged to the vedic age as Aryans. It says that at around 1500 BC Aryans, (which it says was a tribe from the Europe) invaded north India plundering and pushing down the local Dravidians (who it says were the original natives of India) who lived there to down South India. In a nutshell, it says the North Indians of today belong to an Aryan race which came to India from Europe and today’s South Indians are the native Indians (called Dravidian Race!) who lived in North India before the Aryans came! The vedic people who lived in North India during the vedic ages were these Aryans, it says!
First let us see how did they arrive at these dates! It was well known in India in the british period that Vedas pre-dated Christ, since they definitely pre-dated Buddha who lived some 400 years before Christ. Some scholars(!) then said that as per Bible the world was created in 4000 BC(!), and Noah’s flood took place in 2500 BC(!). So they decided that Aryan Invasion of India must have taken place only after this flood and before Buddha, and hence would be around 1500 BC! This is the funniest investigation I have ever heard about. I doubt if anybody can dare to call this a scientific investigation! This is what some call as, adjusting history to be compliant with religious texts
Now let us see some of the obvious proofs that have thrown this theory into dustbin.
Aryan is not a race!First of all Aryan is not a race. No where in the vedas and other ancient Indian text is the terms Aryan used to refer to a race!! Aryan in Sanskrit means Gentleman. It is used in Sanskrit like how in English we use the term Mr, that s all about it!
Even Max Muller who initially termed vedas as childish (only to be later criticized by other scholars as a person who doesnt know even basic sanskrit!), later tried to correct himself in many occassions about the Aryan race! He said:
I have declared again and again that if I say Aryas, I mean neither blood nor bones, nor hair, nor skull; I mean simply those who speak an Aryan languageto me an ethnologist who speaks of Aryan race, Aryan blood, Aryan eyes and hair, is as great a sinner as a linguist who speaks of a dolichocephalic dictionary or a brachycephalic grammar. 
(Max Mueller, Biographies of Words and the Home of the Aryas, 1888, pg 120)
Dravidians was not a separate race!
The people of south India whom the Aryan Invasion theory says were the original natives, are NOT a race separate from the North Indians! They all belong to one and the same race. The ancient Indian vedic race. This is because, the languages of both, the so called Aryan and Dravidian people have their roots in Sanskrit language. Both worship the same Gods. Both have the same epics. Both have same philosophies. Both have histories which date back to BC..
Given these facts, how can then Aryans and Dravidians be two separate races? If Aryans had invaded India then why are Dravidians following the same customs and religion as aryans. How do they speak languages which originated from the same parental language?
Why dont any dravidian folk lore or ancient texts or sayings or stories or epics exist which talk about the so called Aryan invasion? Also why do the vedic texts talk about locations in South India? The Ramayana, Mahabharatha all talk about South Indian locations even below and beyond the main land of India into the Indian ocean like Srilanka! If Aryans were from europe and if they invaded North India and pushed local people down to South India, where did these locations come from?
This proves beyond doubt that there do not exist any separate Aryan and Dravidian races. Instead natives of both North India and South India belong to one single race called the Vedic Indian race!
No mention of Europe!
There is no mention of any location outside the mainland of India in any of the vedic texts! If aryans came from Europe, then why havent the so called aryans mentioned any of the european locations in any of the vedic or related texts? The farthest location away from India towards the west mentioned in the vedas is Kadhahar of present day Afghanistan, which was called Gandhar in the vedic texts and was said to be the kingdom of Shakuni.
Why haven’t any of the texts mentioned about their European locations? Why is there no vedic text which talks about migration from Europe?
No European Rivers!
None of the vedic texts talk about rivers outside India! Everybody knows that rivers were the major sources of water for all ancient civilizations and so all ancient civilizations were centered around the world’s major rivers. Why is there no mention of any European river or a river outside India anywhere in the vedic texts? Wouldn’t a race mention something or the other about its native place in at least one of its texts?
Saraswati River
This is a death blow to the Aryan Invasion theory. According to the Aryan Invasion theory the aryans who invaded India in around 1500 BC settled on the banks of Indus or Sindhu river in North India.
The vedic texts talk about Ganga Yamuna Saraswati as the trio river , the three great rivers of their age. Ganga and Yamuna rivers exist even today in North India and till sometime back Saraswati was thought to be a mythological river. But vedas talk about Saraswati as a mighty river that flowed in the north India during the vedic ages!
There is also the mention of the Ganga Yamuna Saraswati merging at a place called Prayag , which was also called the Triveni Sangam (the current Allahabad in North India where today only Ganga and Yamuna meet). It is said that the Saraswati that merged here with the other two rivers was a subterranean channel of the main river of Saraswati.
The Mahabhartha talks about Saraswati river saying that it dried up in a desert! So it has to be noted here that Mahabhartha can be dated back to the drying up of the Saraswati river!
Recent satellite images and geological excavations have proved the existence of a ancient river in North India, with exactly the same features of river Saraswati described in the vedas and Mahabharatha! Today Saraswati is a dried up river today. Before Saraswati dried up, the present Rajasthan was a lush green area! The drying up of Saraswati created the Thar desert in Rajasthan. Even the current dry beds of Sindh and Baluchistan (currently in Pakistan) were lush green fertile lands before the Saraswati river dried up!
See Saraswati Darshan for a related video and explanation. Below is a image of the path of Saraswati river in ancient India. The source is
Below is a satellite image of the dried up bed of Saraswati river. The source is . Note that in some places the river is as wide as 7 kilometers!
Why did the Saraswati river dry up? The plate tectonics of the Indian sub continental plate and the himalayan sources of this river are thought to be the main reason for that. Sutlej and Yamuna were the main sources of the Saraswati river. As the Indian plate moved up towards the main Eurasian plate, the course of Yamuna got altered in the Himalayas moving more water of Yamuna towards the Ganga river and that of Sutlej got altered to join Indus! This caused a major loss in terms of its water source for the river Saraswati and is thought to have been the cause for its drying up.
Now what does Saraswati river have to say about the Aryan Invastion theory of 1500 BC? Well, the geological excavations give a date of about 4000 BC for the drying up of Saraswati river !
Same Human Race
There are four primary human races in the world. They are Caucasian, Mongoloid, Australian and Negroid. The so called aryan and dravidian people both belong to the Caucasian race where people only get a bit darker as one moves towards the equator which is a natural phenomenon all over the world. More sunlight means more melanin pigment in the skin. As simple as that.
So if Aryan invasion is true then it means that the Caucasian race which first evolved and lived together, then got separated into Aryans and Dravidians and both moved geographies apart, and then became one by Aryans invading Dravidians! Is there any proof for this in AIT?
Why Aryan Invasion Theory?
Then why was the Aryan Invasion Theory created? Well, more than saying created, it was popularized and promoted by the British without investigating its merits and demerits because it suited their divide and rule policy in India. The same way they divided the Hindus and Muslims in India based on religion, they also divided the Indians using this theory as Aryans (North Indians) and Dravidians (South Indians). This was the politics behind this theory. Also read this .
See what modern science and technology has to say about vedic science
In a nutshell, the ancient vedic people were settled in India much before 4000 BC and have nothing to do with the myth of 1500 BC invasion theory! There is no separate aryan or dravidian race. There is one single ancient Indian vedic race with roots IN INDIA. Indus valley civilization is NOT the most ancient Indian civilization. It was probably only a remnant civilization of an ancient Civilization that existed till the end of the Mahabaratha war. The most ancient Indian civilization was therefore the Saraswati valley civilization (or a Ganga-Yamuna-Saraswati civilization) of the vedic age.
Finally read this link to look beyond my thoughts on this invasion that never really happened!
Aryan Invastion Theory – THE END