Controversies in the Earth Sciences

Recovering From an Extinction


How did the mass extinction events of the past change the trajectory of evolution on Earth? How much do human beings impact the future of biodiversity on the planet? In the following reading assignment, we'll explore these topics.

Reading assignment

Read the following articles:

As you read these articles, think about these questions:

  • What is meant by "biological recovery" (i.e., after a mass extinction, how do scientists measure the quantity and quality of life on Earth)?
  • Think about how humans interact with the biosphere. Is there evidence that we are causing changes that are beyond fixing? How do the timescales for recovery compare with various human-induced changes to biodiversity?
  • I find it interesting to think about what the Earth would be like if there had not been mass extinction events in the past. Would hominids have evolved at all? Does our existence now preclude the evolution of some smarter creatures that could have sprung up instead of us?

Tell me about it!

Feel like sharing your thoughts? Use the Questions? discussion forum to do so!