MISSION 2 — Origin of Whales

In the previous level, you looked at the transition from water to land and the evolution of tetrapods. Several groups of tetrapods went on to make the reverse trip—they headed back to the water.

In this level, you’ll put together a tree that summarizes some of the changes that occurred as a group of mammals, closely related to the modern-day hippopotamus, returned to the sea.

Play "Origin of whales" and answer questions 10–12 after you've completed that level.

10-11. Click on the button below to answer questions 10-11. Remember to refer to your completed tree and the species comparison tab if you are not sure of your answers.

12. When two groups of organisms independently evolve similar adaptations, it’s called convergent evolution. Sharks and whales both have streamlined bodies and tail flukes. How do we know that these similarities are because of convergent evolution? Hint: Whales are tetrapods. Are sharks?

Congratulations for completing Mission 2! Click here to begin Mission 3.