Curious about the evidence for evolution? The 11 minute video below from Stated Clearly is a great introductory look at the connections found between species. (Subscribe to their Youtube channel for more great videos.)
The animation opts for communication over overloading the viewer with information. The basic idea is this: shared traits tell us something about the shared histories of species, and in this case, whales.
It helps to get past the frequently stated idea that evolution is not simply a guess—as is frequently misunderstood when some say “only a theory.” Also, did you know there was no first human? See my post, “Why There Was No First Human” for more.