Soil...it’s one the most underrated, and little-understood, wonders on our fragile planet. Here's why. Far from being lifeless dirt, it's estimated that in a single gram of soil, there could be as many as 50,000 species of microscopic organisms, or microorganisms. And in one teaspoon of soil, there are more microorganisms than there are people on the Earth. But much of what lies beneath, in this hidden and deep universe, is still alien to us. Despite being literally under our feet, humans have so far only identified a tiny fraction of the extraordinary life teeming underground. But these animals and microorganisms provide an invaluable role. Millions of years of evolutionary competition have led the microorganisms to produce antibiotic compounds to fight their neighbors. And these compounds form the basis of many of the antibiotics used by us humans. We literally make medicine from our soil. No-one knows how many new treatments could be lying under our feet, waiting to be discovered.