Final answer:
Mass extinctions have historically been followed by an evolutionary burst of new species, which over time can lead to increased species diversity. Historical mass extinctions were natural events, but current rapid species loss is significantly driven by human activity, likening its impact to past mass extinctions.
Step-by-step explanation:
Mass extinctions play a significant role in Earth's biodiversity by both removing and making room for new species. Analyzing mass extinction impacts indicates that while they remove many species, these catastrophic events are oftentimes followed by an evolutionary burst where new species evolve to occupy the emptied ecological niches. This process can contribute to an increase in species diversity over time, though not instantly, reflecting the complexity of ecological dynamics post-extinction events.
For example, the mass extinction that ended the Cretaceous period, about 65 million years ago, caused the decline of many species, including dinosaurs, and allowed mammals to thrive and dominate. Similarly, the end-Permian extinction paved the way for dinosaur diversification. Mass extinctions, therefore, tend to 'reset' ecosystems, leading to long-term increases in biodiversity despite the initial loss of species.
It is important to note that mass extinctions are not solely linked to human activity. However, currently, human actions are causing rapid species loss, creating an impact comparable to past mass extinction events, which were traditionally caused by natural cataclysmic phenomena. Environmental changes, such as global climate change and pollution, contribute significantly to the present rate of extinctions.