It's so cold here! I wish we had the ability to migrate!
I wish we could go somewhere warm and reproduce!
I'm just glad that our offspring will be able to migrate, and stay warm. Then they can stay alive, and reproduce, and then their babies will have the good trait.
I just feel bad for those who couldn't migrate and died. Clearly, they didn't get the good trait.
We made it!
Wow! There are so many more whales migrating now! Next year there will be even more, I'm sure of it!
So the whales who were able to migrate continued to reproduce, and those who couldn't, died before they could have offspring. Soon, all humpback whales were able to migrate, and that trait continues to be passed down from generation to generation. THE END!