What specific biological comparison is used to illustrate the shared ancestry despite massive differences between the two groups?

Answer

Lions and housecats sharing the family Felidae

The text uses the analogy of lions and housecats sharing the Felidae family to explain the biological link between the dissimilar piranha and silver dollar.

What specific biological comparison is used to illustrate the shared ancestry despite massive differences between the two groups?
taxonomyfamilyfishPiranhasilver dollar