Nell Greenfield Boyce

The yellow is there.

It gets exposed.

The red is this completely different thing.

Oh, because the red is actually made brand new in the fall.

Like, Nikki picked up this one maple leaf, which was this kind of mottled red on yellow.

Why does the tree bother to make this red?

Especially since the leaf is about to fall and die anyway.

Why go through this?

Exactly.

Like within days, the leaf is doomed.

So why go to the effort?

Why go to the trouble of making new red colors?

And I should note here that these red pigments are also responsible for the leaves we see as orange.

Okay, like Nikki Hughes picked up this other leaf from like a tupelo tree that was red and dark orange.

And she said if you looked at what appeared to be orange.

Under a microscope, you see lots of red freckles.

Join us as we rustle up some autumn leaf biology here on Shortwave, the science podcast from NPR.

It really depends on who you ask, OK?

I think everybody agrees that the red pigments offer some kind of protection from light.

They can act kind of like sunscreen.