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Geologic Time Scale

The geologic time scale is divided into units and used by scientists to refer to times in Earth history.

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Survival of the Fittest - or Smartest?
Teacher Contributed

Survival of the Fittest—or Smartest?

Why It Matters

Are smarter organisms more likely to survive longer?

Is there a connection between the size of an organism’s brain and its ability to survive? It would seem to make sense. Organisms that over generations have developed higher brain to body ratios should be able to use more reason and logic to help them succeed. But is it that simple? Mostly the big-brained survive

While there are certainly strong arguments for larger brains improving the likelihood for every day survival, what about sudden unexpected mass extinctions? Are the same characteristics that would be linked to long-term survival through natural selection the same characteristics that would give the best chance at surviving a mass extinction?

For example, look at the cockroach: The Cockroach Secret

What are the optimal traits for survival on our planet? Can an organism balance the two different sets of conditions? What would that look like?

Explore More

  1. How do extinctions and radiations of life actually occur? A paleontologist at the University of Chicago, David Jablonski, is trying to answer this question: http://evolution.berkeley.edu/evolibrary/article/jablonski_01 How is Dr. Jablonski trying to investigate mass extinctions? How do mass extinctions “change the rules” of extinctions? Why does he argue that evolution does not necessarily equate to progress?
  2. What can we learn from our past? Use this interactive geologic timeline to explore:
    1. When did biological transformations occur?
    2. What types of biological transformations occurred?
    3. When did mass extinctions occur?
    4. Are there any correlations between the biological transformations and the mass extinctions that occurred through geologic time? Provide an explanation with evidence connecting or disconnecting the two categories.
  3. Are we in the middle of the next mass extinction? What do you think? A Modern Mass Extinction Review the panelist statements on the website, develop your own opinion with supporting evidence, and hold a debate in class to share.

Resources Cited

Emma Marris. Nature. http://www.nature.com/news/mostly-the-big-brained-survive-1.11027

Larry O’Hanlon. DiscoveryEarth. http://dsc.discovery.com/earth/slideshows/surviving-extinction/cockroach-secret.html

David Jablonski. Understanding Evolution. http://evolution.berkeley.edu/evolibrary/article/jablonski_01

PBS. http://www.pbs.org/wgbh/evolution/change/deeptime/index.html


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