Usually history books depict the development of ancient Indian Civilization as starting from Mehrgarh (from 7000 – 3300 BCE) and then moving to the Indus Valley. The Indus Valley civilization flourished from 3300 BCE to 1700 BCE and then the settlements moved to the Ganges plains, probably due to reduced monsoons or due to the disappearance of the Ghaggar-Hakra river system. It was assumed that the Ganges plains had dense forests and people did not have the tools to clear the forests till about 3500 years back.
Our understanding of the development in the Ganges plains are changing due to the work done by the scientists from the Birbal Sahni Institute of Palaeobotany and Lucknow University.

..analysed pollen and chemical signatures in mud dug up from a two-metre-deep hole in the dry lake bed of Sanai Tal, between Rae Bareli and Lalganj in eastern Uttar Pradesh. Ancient pollen yields information about vegetation, while changes in the monsoon are reflected in the signatures of chemical elements buried in lake sediments.
“Our findings suggest that people lived in the Sanai lake region 15,000 years ago,” said Mohan Singh Chauhan, a scientist at Birbal Sahni Institute. But the Sanai lake bed tells a different story: of a seesawing monsoon affecting vegetation and human activity.
The pollen analysis shows that the Ganga plain was a savannah grassland with a few pockets of forests. The scientists also found “cultural pollen” — pollen from plants that grow at sites of human habitation. “Cultural pollen is indirect evidence for human presence and we found it throughout the 15,000-year history of Sanai Tal,” Chauhan said.
The lake itself formed about 12,500 years ago, during a period when the monsoon gained in strength. But the region experienced a 1,000-year spell of dry weather between 11,500 years and 10,500 years ago. During the period, there was a clear decline in the growth of trees around the Sanai Tal, the scientists said.
The levels of cultural pollen — in other words, human activity in the region — also dramatically declined during this dry spell.
The studies show the largest expansion of the lake occurred between 10,000 years and 5,800 years ago, a period corresponding to heavier monsoons. Early during this period, Chauhan said, the region witnessed the beginnings of agriculture.
Excavations at some 9,000-year-old sites in Pratapgarh district, about 100 km east of Sanai Tal, had earlier shown evidence of farming. From 5,000 years ago to the present, the levels of cultural pollen — including pollen from cultivated plants — increases significantly. During this period, the Ganga plain is believed to have witnessed a largescale influx of people.

Previous discoveries in Lahura-Deva site near Sanai Tal have given indication that the Middle Ganga Valley could be home to one of the oldest farming sites in the world, where agriculture developed independently (with respect to West Asia and China).

Previously it was believed that agriculture began in West Asia in a region known as the Fertile Crescent with the domestication of barley and wheat. Later a new Fertile Crescent was discovered in China where rice cultivation began much before agriculture in West Asia. Archaeology in Lahura-Deva site in Uttar Pradesh had recently found carbonised material containing grains of cultivated rice along with wild grass and it was considered to be proof that rice cultivation started in India much before in China.
Now according to American and Taiwanese researchers rice domestication happened in multiple sites, independently

While there is consensus that rice had its roots in Asia, whether it was domesticated in southern China alone or at multiple locations has been under debate.
In a bid to trace the ancestral roots of rice — a cereal eaten by more than half of the world’s population — plant geneticist Barbara Schaal at Washington University and her colleagues analysed the genetic make-up of wild and cultivated rice varieties.
Their studies show that the indica variety was domesticated south of the Himalayas within a region spanning eastern India, Myanmar and Thailand, while the japonica variety was domesticated from wild rice in southern China.
“We now have strong evidence for multiple sites of domestication of rice,” Schaal told The Telegraph over the telephone.
The new studies also suggest that an additional — third — domestication event might have occurred in India, giving rise to a minor variety of rice called “aus” — a drought-tolerant strain cultivated in India and Bangladesh.
The two major rice varieties grown worldwide today — Oryza sativa indica and Oryza sativa japonica — owe their origins to two independent events of domestication thousands of years ago, American and Taiwanese researchers said. [Rice roots lie in east India]

The Haryana Archaeology Department found something significant recently – some huge bricks 4500 years old.

Huge bricks belonging to the ancient Indian Kushan Dynasty have been found near the famous Kurukshetra battlefield, around which the Indian epic, Mahabharata, involving a fatricidal conflict between the Pandavas and Kauravas, is centered. [4,500 year-old bricks found near `Mahabharata’ battlefield Kurukshetra]

Around 4500 years back, Indus Valley Civilization was in existence in the region. The Kushan Empire existed from 1st – 3rd centuries. Either the archaeologists or newspaper reporters have no clue about the chronology of Indian history.