The history of animals spans billions of years, marked by five major extinction events that eliminated entire species while creating space for new life forms to emerge. From the Cambrian explosion that birthed complex organisms to the asteroid impact that ended the dinosaurs, each catastrophe reshaped Earth's biological landscape. Today's animals—from deep-sea creatures to urban wildlife—represent the survivors and descendants of these ancient upheavals, carrying genetic memories of past disasters while adapting to current environmental pressures.