In the previous episode, you met some of my grandchildren. I have another granddaughter who was taking

a walk with me one day around the neighborhood, and I picked up a little piece of stone or gravel that

was nearby, and I showed it to her, and I said, did you know that every stone tells a story? And she had sort of big curious eyes.

And I said, see this stone. See how you can see layers in this stone. That tells me that this stone

formed from layers of mud that were on the bottom of a big lake or a big ocean.

And over time, there were so many layers that the bottom layers of mud became hard as this rock.

And now here this rock is, and we can learn its story.

She had never really thought about rocks as having a story before.

So she then, for the rest of our walk, would run and see a rock somewhere and grab it and bring it to me and say, what's the story of this rock? What's the story of this rock?

It made me wish that I'd paid more attention in geology class back in college.

It strikes me that science is about storytelling, the story behind a rock,

the story of how a planet came to be, the story of how a mountain range rose or was eroded

into a beautiful canyon. In the Bible, we have stories, Genesis stories. Interestingly,

there are two, as if we need more than one story to help us make sense of how the world came

to be. I think we have a sense across cultures, across religions, that if we want to figure out what to do and how to be,

we need to know the backstory that brought us to where we are. And so storytelling from our

natural world as well as from our human stories and individual biographies is so deeply important to us.

In Charles Darwin's notebooks, there's a page where he has a simple tree diagram drawn.

And I just imagine when he drew that tree diagram, probably while he was on a ship heading across the Pacific

ocean, he must have suddenly seen something that really, I don't know if anyone had ever seen

before. He saw that tree diagram became the image for him of a family tree, And he saw that every species had a lineage that it came from

that connected it to other species. And those species were connected like smaller branches to

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