Key Takeaways

KEY TAKEAWAYS

• Extinction is a natural part of the evolutionary process.

• Often extinctions don’t happen in isolation but involve disruptions in the food chain and competition changes in the environment that result in other extinctions.

• It is sometimes difficult to gauge extinction because it involves identifying species, which is also difficult to do.

• Background extinction rates vary throughout geological time but happen in the absence of a mass extinction event.

• There are multiple factors that contribute to mass extinction, which usually involves long-term pressures on the ecosystem and a short-term shock to the environment.

• There have been five major extinction events and numerous minor extinction events in geologic time.