Extinction events refer to periods in the Earth's history when a significant portion of the planet's biodiversity was wiped out, often due to catastrophic environmental changes.

The podcast episodes discuss several notable extinction events, including the Permian mass extinction, also known as the "Great Dying," which occurred around 252 million years ago and is considered the most severe extinction event in Earth's history, as well as the end-Cretaceous extinction that led to the demise of the dinosaurs around 66 million years ago.

These dramatic events have shaped the evolution of life on our planet and provide insights into the resilience and adaptability of various species, as exemplified by the survival of sharks through multiple mass extinctions.