Imagine standing in a 106-acre Utah forest of 47,000 shimmering aspen trees. Now imagine you are not in a forest at all, but inside a single living organism, the heaviest known life form on Earth, and it is quietly fighting for its survival.

This episode unpacks Pando, the Latin for I spread, an ancient clonal aspen that has endured ice ages and wildfires yet now faces an existential threat from hungry deer. We trace the decades-long scientific detective story that proved it was one being, the fierce debate over its age, and the human network now racing to save it.

• Pando weighs about 13.2 million pounds, roughly 6,000 metric tons, and all 47,000 stems are genetically identical clones sharing one root system that reproduces by suckering.
• Aspens are so water-heavy that scientists call them asbestos forests, and Pando uses w ...