Final answer:
Mass extinctions have occurred at various points in Earth's history, resulting in the loss of many species and the emergence of new ones. The graphs of extinctions and family-level diversity can reveal patterns over time. The provided resource offers more details and data on mass extinctions.
Step-by-step explanation:
The fossil record shows that there have been five periods of mass extinction throughout the evolutionary history of life on Earth. These mass extinctions resulted from major changes in global conditions and occurred around 450 million years ago, 360 million years ago, 250 million years ago, 205 million years ago, and 65 million years ago. They mark the ends of geological periods and are characterized by a dramatic loss of species and the gradual origin of new species.
For example, the Triassic period ended around 213 million years ago and marked a mass extinction event. The graph of extinctions of marine life and the graph of family-level diversity can show differences in patterns and trends over time. By comparing these graphs, scientists can gain insights into how mass extinctions have influenced the diversity of marine organisms throughout history.
More information on mass extinctions and their impact on the Earth's biodiversity can be found in Table 38.2 of the provided resource.