This is a

this Scientific American 60 Second Science.

I'm Christopher Intagata.

This Halloween, as you carve jackalanners and make pumpkin pie,

take a moment to appreciate just how far the humble pumpkin has come.

The wild form of a pumpkin is about the size of a tennis ball and it tastes like one.

It's incredibly bitter, it's got a very hard rhyme and it's extremely unpalatable to humans.

Logan Kistler, an archaeologist at the Smithsonian's National Museum of Natural History.

He says, as unpalatable as those early squashes were, they made a tasty tidbit for mastodons.

And we know that because there are deposits of mastodont dung in Florida that are over 30,000

years old. And so in those mastodon dung deposits,

sure enough, what we can find are wild squash seeds.

Kistler says mastodons probably weren't put off

by the gourds bitter taste.

Because a few years back, his team

analyzed the genomes of more than 40 mammals and they found that the larger

the animal the fewer copies of a bitter taste perception gene they tended to have.

And turns out there is an absolutely beautiful correlation between body size and the ability to taste bitter

compounds.

And so what we think is going on is that these are really plants adapted for a landscape with

large herbivores.

They've evolved this bitter toxicity in order to deter small mammals

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