Ancient pollen reveals stories about Earth’s history, from the asteroid strike that killed the dinosaurs to the Mayan collapse

An electron microscope image, colorized, shows different structures of pollen grains, including sunflower, morning glory and primrose. Dartmouth Electron Microscope Facility

If you are sneezing this spring, you are not alone. Every year, plants release billions of pollen grains into the air, specks of male reproductive material that many of us notice only when we get watery eyes and runny noses.

However, pollen grains are far more than allergens – they are nature’s time capsules, preserving clues about Earth’s past environments for millions of years.