Final Answer:
Mass extinctions are profound events in Earth's history, marked by a catastrophic loss of biodiversity. The five major mass extinctions that punctuate the geological record are critical junctures that shaped the evolution of life on our planet.
Step-by-step explanation:
The 5 Major Mass Extinctions:
Ordovician-Silurian Extinction (around 443 million years ago): Caused by glaciations and a drop in sea levels.
Late Devonian Extinction (around 360 million years ago): Possibly linked to climate change and sea-level fluctuations.
Permian-Triassic Extinction (around 252 million years ago): The most devastating, likely due to volcanic activity and climate change.
Triassic-Jurassic Extinction (around 201 million years ago): Potentially caused by volcanic activity and asteroid impacts.
Cretaceous-Paleogene Extinction (around 66 million years ago): Caused by an asteroid impact and volcanic activity.