Evolution Mystery—Internet Lab
Go to: http://www2.edc.org/weblabs/ExploringEvolution/evolution.swf
1. Read each slide carefully. It will tell you what to do.
2. If a word is underlined you can click on it and the definition will appear. Hit the X to
close a box.
The fourth slide (three hypotheses) will be looking at evidence to decide which hypothesis best
describes the ancestry of a whale. The hypotheses you are testing are as follows:
Hypothesis 1: Whales evolved from a land mammal.
Hypothesis 2: Whales evolved from the mesonychids, an extinct group of
Perissodactyls (odd-toed land mammals).
Hypothesis 3: Whales evolved from Artiodactyls (even-toed land mammals).
Record your answers below. This will be the information that will help you solve the
mystery.
1. From slide 2 (blue background), what are the three types of evidence that scientists use to
determine the ancestors or evolutionary history of a species?
At slide 5, click on the DNA molecule
DNA Evidence (Slide 6)—click on each DNA molecule and read about the organisms.
2. List information about the Perissodactyls (odd toes land mammals).
3. List what you learned about Artiodactyls (even toed mammals).
4. What did you learn about Whales?
Click the magnifying glass at the bottom right of the screen to get to
Fossil Evidence—Click on the fossils and read the page.
5. Define: strata
6. Define Sedimentary rock
7. Define Law of Superposition
Open your fossil collection drawer. Click on the rock strata until you find a fossil. Once
you find a fossil drag it into the drawer
8. List in order from oldest to youngest the fossils you found.
9. What did you find out when you clicked on “New Discovery”?
Click the magnifying glass at the bottom right of the screen to get to Comparative
Anatomy—Click on the bones on any organism until you find a bone that is in each one.
10. What homologous bones did you find in the whale, human and horse?
11. Do you see any bones that they all share in addition to the ones you highlighted?
Now you are ready to solve the mystery. Circle the best hypothesis and write which forms of
evidence (DNA, Fossil, and/or Comparative Anatomy) supports this hypothesis?
Hypothesis 1: Whales evolved from a land mammal.
Hypothesis 2: Whales evolved from the mesonychids, an extinct group of Perissodactyls (oddtoed land mammals).
Hypothesis 3: Whales evolved from Artiodactyls (even-toed land mammals).