The Universe Within

Having spent the better part of my working life staring at rocks on the ground, I’ve gained a certain perspective on life and the
universe. My professional aspiration—uncovering clues to the making of our bodies—lies inside the baked desert floor or deep within the frozen Arctic. While this ambition may seem eccentric, it is not much different from that of colleagues who peer at the light of distant stars and galaxies, map the bottom of the oceans, or chart the surface of barren planets in our solar system. What weaves our work together are some of the most powerful ideas that mankind has ever developed, ones that can explain how we and our world came to be.

These notions inspired my first book,
Your Inner Fish
. Inside every organ, cell, and piece of
DNA in our bodies lie over 3.5 billion years of the history of life. Accordingly, clues to the human story reside within impressions of worms in rock, the DNA of fish, and clumps of algae in a pond.

While I was thinking about that book, it became clear that worms, fish, and algae are but gateways to ever deeper connections—ones that extend back billions of years before the presence of life and of
Earth itself. Written inside us is the birth of the stars, the movement of heavenly bodies across the sky, even the origin of days themselves.

During the past 13.7 billion years (or so), the universe came about in the big bang, stars have formed and died, and our planet
congealed from matter in space. In the eons since, Earth has circled the sun while mountains, seas, and whole continents have come and gone.

Discovery after discovery in the past century has confirmed the multibillion-year age of Earth, the sheer vastness of the cosmos, and our species’ humble position in the tree of life on our planet. Against this backdrop, you could legitimately wonder if it is part of the job description of scientists to make people feel utterly puny and insignificant in the face of the enormity of space and time.

But by smashing the smallest atoms and surveying the largest galaxies, exploring rocks on the highest mountains and in the deepest seas, and coming to terms with the
DNA inside every species alive today, we uncover a sublimely beautiful truth. Within each of us lie some of the most profound stories of all.

V
iewed from the sky, my companion and I must have looked like two black specks perched high on a vast plain of rock, snow, and ice. It was the end of a long trek, and we were slogging our way back to camp on a ridge sandwiched between two of the greatest ice sheets on the planet. The clear northern sky opened a panorama that swept from the pack ice of the Arctic Ocean in the east to the seemingly boundless
Greenland ice cap to our west. After a productive day prospecting for
fossils and an exhilarating hike, and with the majestic vista around us, we felt as if we were walking on top of the world.

Our reverie was abruptly cut short by a change in the rocks beneath our feet. As we traversed the bedrock, brown
sandstones gave way to ledges of pink limestone that, from our earlier discoveries, became an auspicious sign that fossils were in the neighborhood. After we spent a few minutes peering at boulders, alarm bells went off; my attention was pulled to an unusual glimmer flashing from a corner of a melon-sized rock. Experience in the field taught me to respect the sensation triggered by these moments. We had traveled to Greenland to hunt for small fossils, so I hunched over my magnifying lens to scan the rock closely. The sparkle that arrested me sprang from a little white spot, no bigger than a sesame seed. I spent the better part of five minutes curled up with the rock close to my eyes before passing it to my colleague
Farish for his expert opinion.

Concentrating attention on the fleck with his lens, Farish froze solid. His eyes shot back to me with a look of pent-up emotion, disbelief, and surprise. Rising from his crouch, he took off his gloves and launched them about twenty feet in the air. Then he nearly crushed me with one of the most titanic bear hugs I have ever received.

Farish’s exuberance made me forget the near absurdity of feeling excitement at finding a tooth not much bigger than a grain of sand. We found what we had spent three years, countless dollars, and many sprained ligaments looking for: a 200-million-year-old link between reptiles and mammals. But this project was no miniature trophy hunt. The little tooth represents one of our own links to worlds long gone. Hidden inside these Greenlandic
rocks lie our deep ties to the forces that shaped our bodies, the planet, even the entire
universe.

Seeing our connections to the natural world is like detecting the pattern hidden inside an optical illusion. We encounter bodies, rocks, and stars every day of our lives. Train the eye, and these familiar entities give way to deeper realities. When you learn to view the world through this lens, bodies and stars become windows to a past that was vast almost beyond comprehension, occasionally catastrophic, and always shared among living things and the universe that fostered them.

How does such a big world lie inside this tiny tooth, let alone inside our bodies? The story starts with how we ended up on that frozen Greenlandic ridge in the first place.

Imagine arriving at a vista that extends as far as the eye can see, knowing you are looking inside it for a fossil the size of the period that ends this sentence. If fossil bones can be small, so too are whole vistas relative to the surface area of Earth. Knowing how to find past
life means learning to see rocks not as static
objects but as entities with a dynamic and often violent history. It also means understanding that our bodies, as well as our entire world, represent just moments in time.

The playbook that fossil hunters use to develop new places to look has been pretty much unchanged for the past 150 years. Intellectually, it is as simple as it gets: find places on the planet that have rocks of the right age to answer whatever question interests you, rocks of the type likely to hold fossils, and rocks exposed on the surface. The less you have to dig, the better. This approach, which I described in
Your Inner Fish
, led me and my colleagues, in 2004, to find a fish at the cusp of the transition to life on land.

As a student in the early 1980s, I gravitated to a team that had developed tools to make headway finding new places to
hunt fossils. Their goal was to uncover the
earliest relatives of mammals in the
fossil record. The group had found small shrewlike fossils and their reptilian cousins in a number of places in the American West, but by the mid-1980s their success had brought them to an impasse. The problem is best captured by the jest “Each newly discovered missing link creates two new gaps in the fossil record.” They had done their share of creating gaps and were now left with one in rocks about 200 million years old.

The search for fossil sites is aided by economics and politics. With the potential for significant oil, gas, and mineral discoveries, there are incentives for countries to catalog and map the
geology exposed inside their borders. Consequently, virtually any geological library holds journal articles, reports, and, one hopes,
maps detailing the age, structure, and mineral content of the rocks exposed on the surface of different regions. The challenge is to find the right maps.