During this period, several strains of immigrants, representing different ethnic families and linguistic ones have merged into it and have contributed to its diversity and vitality.
Several different levels of social evolution co-exist in India; like the hunters, the cultivators, the nomads, the itinerant traders, professionals and different artisans. Hinduism, Islam, Christianity and Buddhism are found here, along with a bewildering number of sects and cults , each with its own rituals and beliefs.
Add to this the modern academic, bureaucratic, industrial and scientific elites and one can find the past, the present and the future living together.
It is very difficult to identify the earliest inhabitants of India. There are no written records about them, since writing was not invented then.
The orally told history is not much reliable. Many minute details could not withstand the ravages of time.
Early human activity in India goes back to the second Inter- Glacial period, between 400,000 and 200,000 B.C. Stone tools found and cave paintings unearthed in many places in the country prove this point very clearly.