Over Earth’s history, mass extinctions in which large numbers of species became extinct have occurred multiple times.
Identify two factors that can contribute to a mass-extinction event.
Explain why some organisms are able to survive an event that causes mass extinction.
Explain how the process of natural selection affects the populations that survive a mass-extinction event.
Two factors that can contribute to a mass-extinction event are natural disasters (such as volcanic eruptions, asteroid impacts, or climate change) and human activities (such as deforestation, pollution, and overhunting).
Some organisms are able to survive a mass-extinction event due to a variety of factors. These include adaptations that allow them to thrive in changing environmental conditions, such as the ability to switch diets or habitats, hibernate, or have a more generalized diet. Additionally, some organisms may have a faster reproductive rate and shorter generation time, allowing them to bounce back more quickly after a catastrophic event.
The process of natural selection affects the populations that survive a mass-extinction event by favoring individuals with advantageous traits that help them survive and reproduce in the new post-extinction environment. Organisms that are better suited to the changed conditions are more likely to survive and pass on their genes to the next generation, leading to the evolution of new species over time. This process helps to repopulate the Earth after a mass extinction and drive the diversification of life.