Secrets in the Silt: Tracking Human History Through Hidden Seeds

If you walked through a forest five thousand years ago, you wouldn't leave many clues behind. Your footprints would wash away, and your wooden tools would rot. But you would leave something else: a change in the air. When early humans started clearing trees to plant crops, the pollen in the area changed instantly. The heavy tree pollen dropped off, and the air filled with the seeds of weeds and grains. Scientists today are digging deep into the bottoms of lakes to find these exact moments in time. They call these