Planet Earth is home to humans and various life forms, but where did our ancestors come from? How did we evolve? While different theories on the origin of life include space and the deep sea, we will focus on deep underground. Numerous microorganisms, that are thought to be close to the common ancestor of all living organisms, have continued to live deep underground for tens of thousands of years. Find out more about the mysterious primitive organisms. Later in the program, we'll introduce a piece of research on sea urchins that could help restore the coastal ecosystem. Discover how clovers are being used to turn malnourished sea urchins into high-quality delicacies.