What if I told you that poisons are all around us?

But just because they're poisons doesn't always make them unsafe.

If it's toxic to an insect, it doesn't always mean it's going to be toxic to us.

But we ought to carefully look at that.

It's Thursday, November 2nd, but surprise, surprise, it's also Science Friday.

Some of my favorite poisons are coffee, eucalyptus, aspirin, and although they're technically

poisons, they weren't designed to hurt me.

Guest host Flora Lickman talks with Dr. Noah Whiteman, evolutionary biologist at UC Berkeley,

and the author of Most Delicious Poison, The Story of Nature's Toxins from Spices to Bices,

about how nature's giant cold churn of poisons shaped life on Earth.

Welcome to Science Friday.

Well, thank you, Flora. It is wonderful to be here.

Let's start with getting our terms straight. Will you define poison for me? Well, that's going to be hard,

Flora, because I like to start with a hard ball on the show. I would say that, you know, my definition of poison as I talk about in the book, it's sort of,

I would say, is a chemical that is produced.

In our case, we're talking about other organisms producing them.

So these are like biological poisons, toxins.

And for me, the definition is really a chemical that damages cells and the

ability of cells to operate. And toxins can be sort of adaptive. In other words, they can be

produced because they give the bear an advantage, usually with respect to other organisms, so an offense

or defense, or something could be toxic like carbon dioxide that is just a byproduct of metabolism.

So the way I think about it, when I think about these poisons as adaptations, is whether they

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