As sure as an automobile could not have been built by even the most enterprising Neanderthal, the appearance of humans on Earth could not have occurred without the myriad of developments that began with the birth of the universe, and continued with the evolution of our planet.
This piece first ran in Printers Row Journal, delivered to Printers Row members with the Sunday
Neil Shubin, a paleontologist and evolutionary biologist at the
Q: As I read "The Universe Within," I kept thinking, I know this, but I don't know this. You cover some familiar territory in geology — plate tectonics, India slamming into Asia, and ocean spreading ridges — but it's in service of a story about biology, something normally treated by itself. Geology is rocks; biology is organisms. What inspired you to bring them together?
A: What I was after was really taking the history of the universe, which people have heard in different ways before, and the history of our planet, but to tell it in a new way, to tell it with the reference point being our own bodies, to show how our own bodies contain the story of the universe and the planet.
The great questions that we face in science and answers to the great questions of science don't easily fall into the "-ologies" we learned in schools: biology, chemistry, physics, astronomy, geology. Some of the most interesting questions we face in science, like why do we look the way we do, or why does the world look the way it does, involve understanding each field, and the interdependence of each field. It's rocks. It's stars. It's DNA. The combined enterprise is necessary to understand the deep questions.
Q: What made you decide to tell this story?
I realized I wanted to write something when it became clear to me that certain facts I take for granted — such as the fact that we have a common history with rocks — some people would find utterly strange. That's the perfect starting point for writing a book. It seems utterly strange to some that parts of our body are linked to great events in the history of Earth.
Q: So most of us aren't making these connections.
A: Just look at our society. We live in a very technological, scientific age, yet there's this huge disconnect between what scientists take for granted and what the general public knows. If you look at controversies of curricula, whether it's evolution or the history of Earth; if you look at discussions of climate change, what you find is a lot of people don't know the basic stories.
Plate tectonics is related to atmosphere, and plate tectonics is related to life. These are interdependent things: rock, air, Earth, life. They're all interdependent, yet we teach them often as separate things. But the reality is, if we want to understand the effects of climate change, or understand how the planet interacts with living things, and how living things have affected the planet, you have to understand the interdependency.
Q: I kept waiting for you to head off into a lecture on global climate change, which seems like the modern illustration of the interplay of these superficially disparate fields. I expected you to say, Hey, if you understand our past, can you see where we're going in the future? But the lecture never comes.
A: I didn't think it was necessary. If the book ended in a lecture, I wouldn't have been happy. I wanted to show, not tell. When we look at 4.5 billion years of the history of the planet, and you see just how linked carbon life and rock has been over time, and how well we know it, I think the conclusion is inevitable. I felt like I could get the point across without lecturing. And if the point is subtler than I intended, I'm comfortable with that. I just tried to stick to the narrative. Anything that took me from that was a distraction.
Q: If you were to provide one example that illustrates the interrelationship between the evolution of Earth and the evolution of us, which story would you tell?
A: I just love the fact that one of the most fundamental properties of our bodies, and one that we share deeply with other creatures, whether it's fleas or algae, is the clock, different kind of clocks. In every cell, we have molecular machinery that tunes us to a 24-hour cycle. It's really profound. I can't imagine a more obvious link to the planet than that.
We all know that from our own experience, from jet lag, or in my case from working in the Arctic. We know how we're tuned to the planet, to light and dark. But what we don't realize is that we're tuned to an almost 24-hour cycle that is inside of us. These biological rhythms affect us so deeply. Some we know about, and we take them for granted. Others we don't know about but are kind of mind-blowing when you think about them and how they relate to flies and other creatures. To me, that's a very deep connection with the planet.
Q: Some of the rhythms are mind-blowing? Which ones?
A: The proofreading of DNA happens with different efficiencies at different times of the day. Our DNA, when it replicates, it makes more errors at night than in morning. So sunlight exposure at the end of the day is more dangerous than sunlight exposure in the morning. If you think about cancer, which is the accumulation of mutations, sun exposure later in the day is more dangerous due to your greater susceptibility to mutations later in the day. It's not because of properties of sun; it's because of properties of the way our DNA replicates.
And there are other things. Kidneys are slowest in the middle of night, for instance. There have been a rash of studies in the last five years looking at shift workers, people who work the graveyard shift, and they have greater susceptibility to cancer and all kinds of diseases and mood disorders. The workings of our bodies depend on a healthy clock. And you can see this across the board. Indeed, many of the genes that we use in our clock — genes called period and timeless — you see them in hamsters, you see them in flies, you see them in worms. It's a deep property of life.
Q: In 2008, you published "Your Inner Fish," showing how our bodies tell the story of evolution. What was the journey that took you from inner fish to a universe in the human body?
A: What happened while writing "Inner Fish," I found myself writing about the universe within too. It didn't fit as one book. So I thought, it will be another book, if I get the mojo for writing again — because I have a day job. But I wrote down the ideas for the inner universe and then forgot about them. During the book tour (for "Your Inner Fish") a lot of questions would come up about it — people were exposed to Carl Sagan, they know he said, "We are made of star stuff."
The subtext of this book is really learning to see the past around you. Once you know history, it kind of changes the way you see the present. It's one of the things you take for granted as a paleontologist and an evolutionary biologist. I had to really work hard to learn to see as a paleontologist, which means I had to fail a lot. To find fossils, right, you have to spend a lot of time not finding fossils. You have to learn about rocks and what they mean and how to interpret them, actually seeing the rock layers and the environmental history of the rocks.
First is pattern recognition, which every field has its own way of doing, whether you're an ornithologist or herpetologist or a paleontologist. Then there's another deeper learning to see — which is much more conceptual, which is knowing about how rocks form, knowing the links between water and rocks and air, and having a sense of, when I look at a cliff, of how that cliff formed geologically. That's the deeper thing.
Jenni Laidman is a frequent contributor to Printers Row Journal.
The Universe Within
By Neil Shubin, Pantheon, 240 pages, $25.95