From the brains behind brains on, this is the Moment of Um.

Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, Um, I'm, I love me a dog and I'll show you my new best buddy.

And I love how different dogs can look from one another.

How wild is it that a golden retriever, a dachshund, and a pug are all the same species?

And speaking of pugs, we got a really fabulous question about these smushed-faced pups from a listener.

Why are Pugs faces so flat?

Pugs have squished faces because they have a slight difference in their DNA that makes the bones of the face not grow as far outwards as they would in a great Dane.

Hi, my name is Jeff Schoenbeck.

I'm a researcher based at the University of Edinburgh over here in Scotland.

I study animal genetics.

So why do dog breeds look different from one another?

Well, I think it has a lot to do with back in time.

It became popular almost like a

hobby to breed dogs. A certain style of dog fitted certain families or had certain uses. And so what

we think happened is maybe a couple hundred years ago, breeders were breeding pugs or or some other breed of dog. And at some point, there was a

change in DNA and that affected how the face, the bones of the face, took shape. You know,

I like to think, well, the breeder looked at these

puppies and these puppies had a very, very flat face. And they really liked that look. And so

they kept on breeding for it. And that way, they can kind of make a short face even shorter and

shorter over time. There's some evidence that perhaps there's additional things that are going on the

skin to wrinkle it more as well. So that's what happens in pugs. But then when we go over to

another breed of dog, like the bulldog, or we go to the Boston Terrier, or Brussels-Grafon,

...