By clicking on the timeline at left, you can see how these features changed as whales evolved.

What dramatic changes occurred to the forelimb?

a) The shoulder blade got smaller and finally disappeared

b) The bones in the hand spread out and got very broad

c) The upper arm bone (humerus) got longer

The hand bones spread out so that the whole limb got shorter and broader.

As these features changed, so did their functions. Let’s explore...

Take a closer look at the different bones. Try again...