Category Archives: Earth History

Biology, Earth History

Earth History Timeline

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Now that students better understand how scientists use radiometric dating to determine the age of physical items and structures, it is time to look into the deep history of Earth.  Students should research the following events, determine when they occurred, and construct a timeline of the events:

  • First dinosaurs
  • Formation of Mount Rainier
  • First hominids
  • Break up of Pangea
  • First vertebrates
  • First life (bacteria)
  • First modern humans
  • First oxygen in the atmosphere
  • First land plants
  • First animals

On Friday, we made a timeline of the last billion years of Earth history on the football field:

IMG_1553
1st Period Timeline
4th Period Timeline
6th Period Timeline

After we debriefed the timeline exercise back in the classroom, if time permitted, students watched one of the two videos below:

There’s Mounting Evidence The African Continent Is Splitting in Two

Biology, Earth History, Evolution

Radiometric Dating

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Last week, we learned about Darwin’s voyage and how he collected data to formulate his theory of evolution.  We went on to study biological classification, using the system devised by Linneaus way back in 1735.  Previously, we learned that scientists collecting were able to date common ancestors of humans to over 3 million years ago.  Our work over the next few days will be to learn how scientists use radiometric dating to estimate the age of really old samples.  We will begin an introduction to chemistry, focusing our efforts on understanding the difference between carbon-12 and carbon-14 atoms.  Class notes are pictured below:

Next, we will watch a video introducing radiocarbon dating:

After the video, we will begin the Radioisotopes Activity.  We will read through the first few pages, and then tomorrow students will work with a partner to complete the activity which is anticipated to wrap up by Wednesday.