Final answer:
The extinction of a single species doesn't indicate an extinction event because multiple extinctions are typically needed for an event to occur. Mass extinctions, which are sudden and dramatic losses of biodiversity, have occurred five times in Earth's history. These events result in a significant drop in diversity and have a hugely disruptive effect on the development of biodiversity.
Step-by-step explanation:
The extinction of a single species doesn't indicate an extinction event because multiple extinctions are typically needed for an event to occur. Mass extinctions, which are sudden and dramatic losses of biodiversity, have occurred five times in Earth's history. These events result in a significant drop in diversity and have a hugely disruptive effect on the development of biodiversity. While species can be resilient to environmental stresses, there can be collapses in genetic, organismal, and ecological diversity when pushed beyond their limits.