For a long time, maybe centuries, scientists have been trying to pinpoint just what distinguishes man from animals.
For a long time, many people just held to the Christian idea that man is different because God created us to be superior and have "dominion" over the Earth, but that's been weakened by the acceptance of the heliocentric model that says Earth is not at the center of the universe after all.
Then Darwin popularized the idea that man was not even divinely created, which puts our favor in question.
At first anthropologists said that man is the only animal that uses tools, but we've since found many other animals that use them.
Similarly some have said that only humans use language, and that's also wrong.
So what if anything separates man from animals?
The chin.
No other animal in the world has a chin.
Nobody really knows why we have chins or what function they serve, but we do have them, and no other primate or other animal does.
Yay humans!