Those Who Know the Past

Those Who Know the Past

Looking out my small office window in Chicago, I see all the signs of a modern urban environment. Across the nearby soccer field, a mix of recent and early twentieth-century buildings are visible. City buses, trucks, and cars roll past, dodging pedestrians, and planes fly overhead on their way to Midway or O’Hare fields. But if I blink and close my eyes, I can imagine a different scene—some sixteen thousand years ago. Where I now sit there is a lake, the ancestor of today’s Lake Michigan. Looking to the east, I see the edge of a huge glacier that stretches all the way to what is now Canada. The melting of this ice sheet has produced the lake in which I am submerged. Toward the west and south I see the other shores of the lake, ridges and beaches formed from material left behind as the glacier retreated. And walking near the shore are mammoths and mastodons and other animals that will meet their final demise not long after the ice sheet disappears.

When I blink and close my eyes again, I have traveled back more than three hundred million years. I am surrounded by steaming tropical forests. I see huge trees, but they look nothing like those of today. Only the ferns are familiar. I cannot smell or see flowers. Gigantic dragonflies flit through the leaves, and an enormous centipede roams underfoot. I see the occasional amphibian or reptile, but there are no birds or mammals. Rivers flow nearby with odd scorpion-like animals and fish swimming in them. Looking southwest, the rivers that course through the forest end in a delta that sits at the edge of a warm ocean.

One more blink takes me back to four hundred million years ago. I am back in the water, but this time I am in a warm tropical ocean that stretches out in all directions. Looking down, I notice that the seafloor is flat and somewhat featureless. Strange animals that look like giant pillbugs walk along the bottom, and large animals that look like squid stuffed into giant ice cream cones swim above them. In the distance, the waves break on what appears to be a giant coral reef.

Unlike the children in Willy Wonka and the Chocolate Factory, I have not entered “a world of pure imagination” when I think about these ancient versions of Chicago. Each of these cerebral trips back into what the writer John McPhee called “deep time” is based on rocks and fossils found throughout the region, all of which I have seen. These samples were collected by me and by the many other scientists who have worked in the area. I am a paleontologist, and these explorations of deep time and the life that lived in the past is what I and my colleagues do. My goal for my  new book is to explain how we make these explorations, why we do them, and why they are important to society at large. In particular, I want to show readers that what paleontologists know about the history of life on Earth is critical for protecting its future.

Paleontology is one of the most familiar and accessible of all sciences.  From a young age, children are familiar with the names and life habits of dinosaurs. Media reports of new fossil discoveries appear several times a week. Despite this popularity, misconceptions about paleontology and paleontologists abound: we are confused with archeologists; we study only dinosaurs; or all fossils are rare and valuable. One purpose of my book is to dispel these misconceptions. Another is to describe the “big questions” that drive the field and the methods and data that are used to approach them. I introduce readers to a diverse group of paleontologists and the wide range of topics and interests that motivate them, and readers will hear them speak in their own voices on various topics. And I frankly discuss the trials, tribulations, and joys of pursuing a career studying the history of life.

Explorers of Deep Time is not a textbook nor a collector’s guide to fossils. Readers will not be bombarded with a plethora of Latin species names or terms. Instead, I focus on the practice of paleontology, the “how do we find out” part of our science. I also address some of the internal and external controversies of the field, such as the commercial sale of fossils and the value of teaching evolution. Rather than being an “old science,” readers will learn that paleontology is a young and vibrant field in this day of DNA sequencing and gigantic supercolliders. Incorporating these new technologies, paleontology has shown tremendous relevance for understanding the environmental problems we will face in the future. Finally, I hope I can convince readers that paleontologists probably have more fun doing what we do than any other group of scientists.


Adapted from Explorers of Deep Time: Paleontologists and the History of Life on Earth by Roy Plotnick. Copyright (c) 2022 Columbia University Press. Used by arrangement with the Publisher. All rights reserved.


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