With a jaunty bow tie and boyish enthusiasm, Bill Nye the Science Guy has spent decades decoding scientific topics, from germs to volcanoes, for television audiences. Last February, the former engineer defended the theory of evolution in a debate with young-Earth creationist Ken Ham, a vocal member of a group that believes the Earth is only 6,000 years old. Nye's decision to engage Ham kicked up plenty of criticism from scientists and creationists alike.

The experience prompted the celebrity science educator to write a "primer" on the theory of evolution called Undeniable: Evolution and the Science of Creation. In his new book, Nye delights in how this fundamental discovery helps to unlock the mysteries of everything from bumblebees to human origins to our place in the universe.

Who do you hope will read this book?

Grown-ups who have an interest in the world around them, people coming of age who have an interest in science, people who still want to know how the world works.

This is the big concern of mine with respect to the organization Answers in Genesis and Ken Ham and all those guys: their relentless, built-in attempts to indoctrinate a generation of science students on a worldview that is obviously wrong.

I worry about these kids—they're part of my society. We can't raise a generation of students who don't understand the fundamental idea in all of life science, any more than you want to raise a generation of kids who don't understand chemistry or physics or arithmetic.

How and when did you first encounter creationism?

About 20 years ago. I was a member of the Northwest Skeptics, which is the Seattle-based skeptics organization. We met people who insisted that the Earth was 6,000 years old. The inanity took my breath away. When you understand anything about astronomy or have just a rudimentary understanding of radioactivity, the Earth is patently not 6,000 years old. It's silly.

It's been said that a good way of convincing people of something is to appeal to their emotions. What do you think?

That's my business! In the book, I purposely spend a lot of time in the first person. The reason is, we find stories compelling. Stories are how we remember things, how we organize things.

By telling a story in the first person, it's hard to dismiss. If I say, "I remember the time I met Ivan the gorilla," it's really difficult for the listener or reader to go, "No, you don't!"

When you say, "I feel," it's really hard for the reader to say, "No, you don't." Yes, I do. I did a lot of that in the book.

View Images A fascination with bees and flight drew a young Bill Nye into the world of science and evolution. Photograph by Mark W Moffett, National Geographic

What first drew you to science? Was it the emotional connection?

When I got involved, in a very, very, very small way on the Spirit and Opportunity rovers, I claim that I was the guy waving his arms, jumping up and down, saying, "We've gotta put a message to the future on this thing." And the guy who really crystallized it was the principal investigator, Steve Squyres. I had written "the thrill of discovery," and he said, "No, the joy of discovery."

He's absolutely right. What we want everybody to experience in science education and science is the joy of discovery.

And I definitely experienced that when I was a little, little kid. I watched bees and watched bees and watched bees and just said, "What's the deal? How can they possibly do this? Up and down, back and forth, hovering, filling up their pollen baskets." Pollen looks like it weighs twice what they do, and they have tiny, tiny wings. Flight has always fascinated me.

Why has there been such an assault on science in recent years?

I ponder this all the time. Our ability to share information has been fantastic, but I don't think we, as a society, have matured enough to sort out the good from the bad. If you have enough electronic influence, you can promote ideas—which, in this case, are obviously wrong. But you can do it loud and clear.

The other thing that's happened is that fossil fuel companies have successfully introduced the idea that scientific uncertainty is the same as doubt about the whole thing. This has gone from climate change to all sorts of things.

But I think taxpayers will realize that you can't remain competitive in the world, economically, without successful scientists and especially engineers—people who use science to solve problems and make things. I think people on both sides of the aisle will soon grasp that you can't be successful and ignore science.

View Images One of the most fundamental ideas in explaining life on Earth is the theory of evolution, says Nye. Photograph by NASA Earth Observatory

What one or two points do you want people to take away from this book?

Evolution is a discovery. We discovered evolution. Two guys [Charles Darwin and Alfred Russel Wallace], at about the same time, reached the same conclusion about nature.

The other thing is that we are all in this together—everybody on Earth. There's no such thing as "race." There are tribes and societies, but we're all one species because humans moved around the world so recently, in evolutionary terms.

Anything else?

Evolution fills me with reverence for our place within the cosmos, what I like to call "our place in space." We're the product of stardust, brought together by gravity—we're at least one of the ways that the universe knows itself. That, to me, is astonishing.

The other thing to realize is, the Earth is our home. It's all we have. This is where we make our stand, as Carl Sagan says. We ain't going anyplace else, not readily.

So, we've gotta figure this out. We've gotta take care of this place. Those discoveries come from understanding evolution.