Prayagraj: Indian scientists have cracked the code to pinpoint the origins of farming thousands of years ago – and it’s all thanks to microscopic pollen grains. This breakthrough research lets them differentiate between pollen from crops like wheat, rice, millets and maize, and that from wild grasses, just by looking at size.The discovery promises to revolutionize studies of ancient human settlements and agricultural activity in the Central Ganga Plain — a region often referred to as India’s food basket.The study, published in the international journal Sage, is authored by senior scientist Swati Tripathi from Birbal Sahni Institute of Paleosciences, Lucknow, along with Arti Garg, former senior scientist from Botanical Survey of India (BSI), Prayagraj, Arya Pandey and Anupam Sharma (BSIP), Priyanka Singh (Indian Institute of Geomagnetism, Mumbai), and Anshika Singh (department of botany, LU).Pollen grains, tiny particles released by plants, can survive thousands of years buried in soil and river sediments due to their tough outer layer. Scientists study these fossil pollens in a field known as palynology to reconstruct past environments, climate patterns, and human activity. A key focus is anthropogenic marker pollen—pollen from crops or other human-associated plants — which acts as a direct indicator of ancient human influence on landscapes.Till now, Indian researchers used European standards to tell apart cereal and non-cereal pollen, which wasn’t always reliable for our context. This new study gives us a homegrown benchmark, based on data from the Ganga Plain, making it way easier to pinpoint early farming in India.The researchers examined 22 species of grasses — eight cereals and 14 wild grasses — using advanced microscopic techniques, including light microscopy, laser-based confocal microscopy, and high-resolution electron microscopy. They focused on two key measurements: the overall pollen grain size and the diameter of the annulus, a ring-like structure on the grain. The study established a clear “paired biometric threshold”: cereal pollen consistently has a grain diameter above 46 micrometres and an annulus size over 9 micrometres, except pearl millet which has smaller size, while wild grasses are smaller.In addition to size, the scientists also analyzed surface patterns on the pollen grains, which provided extra clues about the plant species and the environmental conditions in which they grew. Together, these findings create a comprehensive reference dataset that allows fossil pollen to be identified up to the species level, enabling researchers to more accurately trace the appearance of agriculture and settlement activity over the past 10,000 years.“This discovery will significantly improve the accuracy of studies on ancient agriculture, land use, and human impact on ecosystems. It will also help archaeologists and environmental historians understand how humans gradually transformed the fertile plains of the Ganga into a major agricultural hub,” said Tripathi.In simple terms, tiny pollen grains are now helping scientists unlock the story of India’s agricultural beginnings, providing a powerful window into the region’s past and how human societies shaped the landscape over millennia, adds Garg.
