If the mass extinction that occurred 250 million years ago and 64 million years ago may have been due to gradual process or?

The mass extinctions that occurred 250 million years ago (the Permian-Triassic extinction) and 64 million years ago (the Cretaceous-Paleogene extinction) likely involved both gradual processes and sudden catastrophic events. The Permian extinction may have been driven by prolonged volcanic activity and climate change, while the Cretaceous extinction is widely attributed to a massive asteroid impact coupled with volcanic eruptions. Both scenariOS highlight the complex interplay of environmental stressors and abrupt events that can lead to significant biodiversity loss.