Beth Shapiro

So a polar bear female will ovulate in the presence of a male.

So the male comes up to her and will mate her.

The other way around, if a polar bear male had encountered a brown bear female, he's probably more likely to eat her than to mate her.

But that's weird then.

So why do we always find the hybrids living with brown bears instead of living with polar bears?

And the polar bear biologists who we've worked with, I've worked a lot of time with Ian Sterling, who's a fantastic polar bear biologist from Canadian Wildlife.

And his hypothesis is straightforward that they can't successfully hunt seals if they don't have that white fur.

It does, right?

Yeah.

But they hide in, I mean, they even have those things where they cover their nose with their hand, the black nose with their hand because the black nose.

I know.

It's insane, right?

That's nuts.

Biology is cool.

But they also hybridize just given the chance to do so, right?

Because biology doesn't recognize species concepts, right?

Biology doesn't care that that animal is called a brown bear by us and that animal is called a polder bear.

They run into each other.

They're like, cool, just like our Neanderthal ancestors.

This is actually how we discovered it, because we found that the place where brown bears hybridized with polar bears during the last ice age was probably the ABC Islands off the coast of Alaska, because the ice was that far south at the peak of the last ice age.