A TIMELINE OF EARTH AND EVOLUTIONARY HISTORY
1. Brainstorm with a partner to try to put the following events in order from earliest to most recent.
- Humans appear
- first land plants
- first fish
- first insects
- first dinosaurs, mammals
- first birds
- Earth forms
- first multicellular organisms
- first flowering plants
- first eukaryote
- oxygen starts to accumulate in the atmosphere
- extinction that killed the dinosaurs
- agriculture begins
2. Before class on ______, find out when each of the events above is thought to have happened (i.e., how many thousands, or millions, or billions of years ago) and write it down next to the event.
______
3. Use a meter stick to draw a continuous line down the middle of a 5 m strip of adding machine tape. Use the following scale: 1 meter = 1 billion years.
a. How many years does 1 mm represent? ______
4. At one end of the tape, a few inches from the end, draw a line across the tape and label it present.
5. Measure off a distance that represents 4.6 billion years ago (b.y.a). Draw a line across the tape and label it Earth’s beginning.
6. Now, using the correct dates for the events above, put them in their proper places on your tape.
Analysis:
1. Which era is the longest? The shortest?
2. In which eras and periods did dinosaurs, mammals, flowering plants, and birds appear on Earth?
3. Which group lived (or has lived) on Earth a longer time, dinosaurs or mammals? Calculate the age range of each.
4. Which major group flourished only after the dinosaurs became extinct?
5. Where did life exist during the early part of the Paleozoic era? What fossil evidence leads to this conclusion?
Sources:
http://www.ucmp.berkeley.edu/help/timeform.html The University of California Museum of Paleontology has a hyperlinked timeline of Earth history. Check it out; it’s great!