Evolution/Geologic Timeline
Background Information:
Remember evolution is the change in species over time. How long is that time? Does the time vary? In this activity you will learn how much time is involved in evolution.
Procedure: You are going to make a timeline out of the table below.
1. Fill in the “distance on timeline” column in the table. The scale of your timeline is below.
1 millimeter (mm) = 1 million years
You will also need the following information.
1 meter (m) = 100 centimeters (cm)
1 m = 1,000 millimeters (mm)
1cm = 10 mm
2. Take the 5 meter adding machine tape. At the far right side make a straight vertical line and mark that “present day”. This is 0 years ago.
3. From that line measure 5 mm. Make a mark. Connect the points together with a line and mark it event number 16. Also mark the times. See below.
4. Repeat for the rest of the event numbers and times. Make sure you always start from 0 (present day).
Event Number / Event / Years ago / Distance on timeline1 / Earth forms / 4.6 billion / 4.6 meters
2 / Oceans form and cover Earth / 4.0 billion
3 / Oxygen present in Earth’s atmosphere / 3.5 billion
4 / Bacteria appear (unicellular) / 3.5 billion
5 / Soft bodied, multicellular organisms develop / 600-700 million
6 / 1st mass extinction / 544 million
7 / Explosion of invertebrate life in seas / 544-505 million
8 / Early vertebrates appear / 438-408 million
9 / Fish appear, amphibians reach land, forests grow / 408-360 million / 360-408 millimeters (36.0-40.8 cm)
10 / Reptiles appear, insects abundant, winged insects appear / 320-286 million
11 / Reptiles dominate, mass extinction of marine invertebrates / 286-245 million
12 / 1st dinosaurs appear, first mammals appear / 245-208 million
13 / First birds, first flying reptiles / 208-144 million
14 / Continents move to present day locations, dinosaurs dominate, mass extinction at the end / 144-65 million
15 / Mammals flourish, flowering plants thrive / 65-5 million / 65 mm-5mm
16 / 1st Humanoids, modern humans appear / 5million-100,000 / 5 mm-0mm
17 / Dogs evolve from wolves / 10,000
5. Once you have completed the timeline, bring it up to the teacher to check for accuracy.
Questions—Answer the following questions in complete sentences.
1. Did new species appear at the same time as others? Explain.
2. Describe the how long it took for life to first appear on Earth.
3. There were several mass extinctions on Earth. What are mass extinctions? Identify at least 2 causes of mass extinctions? (p 194, p 187, p192
4. Described what happened after mass extinctions.
5. (A) Compare how long humanoid type life forms have existed on Earth to that of Earth’s existence.
(B) Compare how long humanoid type life forms have existed on Earth to other life forms.
6. Dogs first started evolving about 10,000 ya (years ago). Is this a long time, geologically speaking?
7. Did the Earth stay the same for 4.6 billion years or were there changes? Explain.
8. What is Pangaea? Explain what happened to it between 260 mya to the present day (see page 192).