Elizabeth Preston

And they pass them around all day long.

But one interesting thing about the marmosets and tamarins is that this is the only other primate where you see babbling.

So you can hypothesize that in our evolutionary past, our babies had to evolve to get an adult's attention, to be charming and engaging because it's in the baby's interest for caretakers around it to want to hold it and want to cuddle it and want to share their food, right?

And so perhaps this need to engage with the caretakers around it caused both our babies and the marmoset and tamarin babies to

to evolve this cute babbling behavior.

It's not only practicing speech, but maybe just a way to be adorable.

Oh, I don't know about that, but that sounds interesting.

Definitely.

All kids want snacks all the time.

At least that's true in my house.

But one species where this actually has been studied a lot is among the poison frogs.

So there are a lot of types of poison frogs.

They live in Central and South America.

They're these colorful frogs in the rainforest.

And they've evolved to be really attentive parents.

The reason that they have to be attentive parents is that unlike the frogs you might be more familiar with in your own neighborhood, those frogs lay their eggs in a pond.

And when the eggs hatch, they become tadpoles, which are basically a fish.

And they're already in a pond, so it's fine.

But the poison frogs live in the rainforest.

And so when their eggs hatch, now you have a fish in the forest.