Final answer:
Mass extinctions greatly reduce overall biodiversity, but eventually biodiversity levels return to pre-extinction levels. These events have a dramatic short-term impact on ecosystems, but their long-term impact should not be underestimated.
Step-by-step explanation:
Mass extinctions have a dramatic short-term impact on the nature and components of ecosystems. They greatly reduce overall biodiversity, with 75-95% of species becoming extinct during these events. However, despite the initial loss of biodiversity, biodiversity levels eventually return to pre-extinction levels. This is because recovery from past mass extinction events has taken place in a relatively short geological time period, although it may still be of the order of a few million years
These events are significant because they disrupt the development of biodiversity and lead to collapses in genetic, organismal, and ecological diversity. The resilience of terrestrial and marine biotas to environmental stresses is not infinite. Human activities, which have drastically reshaped the natural world over a long period of time, exert intense and widespread pressures on biodiversity.
Overall, mass extinctions have a noteworthy short-term impact on biodiversity, but in the long term, biodiversity levels tend to return to pre-extinction levels. However, the impact of mass extinctions on the development and resilience of biodiversity should not be underestimated.