The Vedic Age

The Vedic civilization was sustained by agriculture. What triggered the agricultural revolution was the release of the frozen waters- an event that transformed not only India but also East Asia. Temperatures rose as much as 5 degrees Celsius, melting the Himalayan glaciers in which enormous quantities of fresh water had been locked up as ice and snow. Higher temperatures also meant increased evaporation and a more vigorous monsoon. Lakes and rivers had two new sources of freshwater- melting glaciers and the abundant monsoon. Great perennial rivers burst forth from the Himalayas- Indus, Sutlej, Sarasvati (now dry), Yamuna and Ganga in North India, and Brahmaputra, Irrawady and Mekong to the east.
Of these the Sarasvati was the greatest- as the Rigveda describes, and as science now confirms. It was flowing in all its majesty from 8000 B.C. to 4,000 B.C. It began to decline about 3500 B.C. and dried up completely in the 2200 B.C. to 1900 B.C period. Considering that agriculture had been mastered in Southeast Asia-in Thailand and the Mekong region-no later than 10,000 B.C. or 12,000 years ago, the Sarasvati dates give a reasonable approximation for the Vedic period. It means that in the post Ice Age period, it took some 2000 years for agriculture to make its way from its place of origin to the Sarasvati river area. This is probably an underestimate.
This scenario is receiving increasing scientific support. River delta cultivation of rice is known both in India and further east in Asia. This means the skills needed for growing food grain were already in place 10,000 years ago, even as newer crops like wheat and barley came to be cultivated later. Genetic analysis has shown that Indian livestock-the humped bull and the water buffalo-are of East Asian origin. Indian and Southeast Asian human populations also are genetically close.
We may note here that the claim that Indians, especially the upper castes, carry European genes is unfounded. The M17 genetic marker, which is supposed to be a 'Caucasian' trait, occurs with the highest frequency and diversity in India. This means that among M17 carriers, the Indian population is the oldest. The proponents of the now discredited Aryan invasion have got both the origin and the direction of movement wrong. It is different, however, with Southeast Asian markers: their frequency in both South Indian and North Indian populations is surprisingly high. This shows extensive gene exchange between Indians and Southeast Asians.
So, on the basis of ecology, agriculture, livestock, and human populations, we may safely conclude that the seeds for the growth of agriculture and animal husbandry needed to sustain the Vedic civilization existed by 10,000 B.C. The long-standing maritime connections between India and Southeast Asia going back to the Ice Age facilitated the transfer, beginning with river delta cultivation, once humans mastered the skill of reproducing the phenomenon that occurred naturally at places like Tonle Sap.
Space, time and civilization
To understand the origins of Vedic civilization, we need to recognize that India and East Asia-the monsoon belt between the Indus and the Mekong rivers-form a single ecological and cultural zone. It is dominated by two natural forces- Himalayan glaciers and the summer monsoon. The easiest means of communication has always been by sea. A second line of transit was a more difficult land route running north through Thailand, Burma and Assam. Expansion along this route was facilitated by the practice of 'slash and burn' agriculture, in which large tracts of forest are burnt down for cultivation. This forced people to be on the move in search of new forest, because it takes several decades for the burnt forest to regenerate. This was probably how agriculture and livestock spread to parts of India from its origin in the east, near the Mekong region. It accounts also for the close biological connections between the species of the two regions.
Civilization, of which the Vedic is the oldest recorded, is a post Ice Age phenomenon. It was made possible by the forces of nature that the calamitous ending of the Ice Age unleashed. This has been evolving not for centuries but over more than 10,000 years- from the birth of agriculture in a peculiar ecological niche to the present day. It shows that no civilization evolves in isolation. Our genes came from Africa, agriculture from Southeast Asia and modern technology mostly from the West. India too contributed many important things- from mathematics to metallurgy.
Ultimately it is nature that makes everything possible. She is her own mistress and chooses her own place and time to unleash the forces that bring about momentous change. History is only an extension of natural history.