Lab:  Geologic Timescale

1)    Measure 5.0 m of adding machine tape.  At 1 cm from one end, draw a straight line.  Label it TODAY.
Measure 4.6 m from the TODAY line.  Draw a straight line, label it AGE OF EARTH.
Mark off & label the metric distances you calculated for each geologic event.
Label each geologic event & the age associated.
If you know what the organisms looked like for each event, draw a picture of them!

2)    Using your geologic timescale and a computer, place the following events on the appropriate places on paper. Mark long periods with a horizontal line from beginning to end with a colored pencil.  Label these.

5b--Geologic Timescale Lab--AP Env Sci

a) trilobites appear, flourish, and become extinct.
b) first flowing plants (angiosperms) appear.
c) dinosaurs appear, flourish, and become extinct.
d) first birds appear
e) first reptiles appear
g) first mammals appear
h) early humans appear


Answer the following questions:
1)    Does the scale you made measure relative time, absolute time or both?  Explain.
2)    When did humans first appear?  What is the scale length from that period to the present?
3)    Calculate the percentage of time passed for each era.
4)    Create a table showing the percentage of time for each of the epochs of the Cenozoic.
5)    Write a paper, to be included with this lab.  Include the following:
Why should we care about the geologic timescale?  What can we learn about the environment from the past?  Should we take care of our environment or just live in it since we are just a species within the Cenozoic Era of geologic time?  Why?  Why not?  Do you believe endangered species will become extinct?  Do you believe these extinctions are due to environmental causes or are they man-made?  Explain.  Within your answer, include examples of species that are currently on the endangered list and try to figure out the cause of their endangerment.  You may want to relate this to the 10 signs we’re in a mass extinction list.

© lbranch 2013