You're listening to Shortwave from NPR.

Hey, Shirt Wavors, Regina Barber here, and today we're entering the world of our favorite

squirrel-seeking friends.

Before there was Lassie, before Toto, before Scooby-Doo, there were ancient wolves and ancient

humans, and they kind of became pals.

The circumstances are kind of unclear, but at some point both species realized, you know,

this is not a terrible partnership to form.

This is Katie Wu.

She's a staff writer at The Atlantic, and recently, she dug into why dogs act the way they do

and how dogs became man's best friend.

They came in the contact with each other, maybe because the wolves were attracted to garbage,

dumps, and human encampments, or because they just got really friendly while they were

hunting in the same spaces.

If I'm a wolf, I can get a consistent source of food.

You know, this nice tall, bald ape thing likes to pet me, and I feel a lot safer.

And the humans are thinking, wow, this is an apex predator.

It can help me hunt, can guard my family.

And it's just pretty cool to play around with, and the two species started to co-evolve.

Suddenly, there was this really friendly wolfish lineage that kept on coming back, helping

out the humans and getting belly rubs in return.

And eventually, settling into these specific doggy jobs.

It was almost a dog industrial revolution where they super-specialized into these careers

...