It’s an iconic image: A polar bear perched on a lone ice cap, drifting at sea. Is that the fate climate change has in store for this powerful Arctic inhabitant? In 2004, the discovery of a fossil polar bear jaw on Svalbard, a Norwegian archipelago, suggested another possibility. The fossil came from a bear that had lived between 110,000 and 130,000 years ago, an era that was warm — even warmer than today.
But studies of the genome extracted from the fossil showed the ancient bear had much greater genetic diversity than modern polar bears. Scientists hypothesized that when ice diminished in previous millennia, polar bears moved to land and interbred with brown bears, whose genes could have helped them adapt to the warmer weather. With possibly fewer genetic resources, today’s polar bears may not fare as well.
BOOK REVIEW — “Ends of the Earth: Journeys to the Polar Regions in Search of Life, the Cosmos, and Our Future,” by Neil Schubin (Dutton, 288 pages).
That’s one of the many unexpected discoveries covered in “Ends of the Earth: Journeys to the Polar Regions in Search of Life, the Cosmos, and Our Future,” the latest book by paleontologist and evolutionary biologist Neil Shubin. And the tenuous fate of the polar bear hints at the question at the heart of his narrative: What is it about the polar regions that seems so important to our understanding of the environment — and ourselves?
Although polar regions only make up 8 percent of the total surface of the Earth, their influence is far greater than one might expect. “Almost 70 percent of all the planet’s fresh water is frozen in ice,” Shubin writes. “On land, permafrost in the polar regions holds 1,600 billion tons of carbon — roughly double that in the entire atmosphere today.”
“Locked in the soils and ice of the poles are clues to our past and things that will shape our planetary future,” he continues. “Every milestone of human evolution, from the origin of our species to the establishment of our social structures and technologies, arose during a time of ice at the poles.”
Shubin, a professor at the University of Chicago who has spent decades leading expeditions in the Arctic and Antarctica, is the author of popular science books like “Some Assembly Required: Decoding Four Billion Years of Life, from Ancient Fossils to DNA” and “Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body.” But he might be best known for his 2004 discovery of Tiktaalik, a 375-million-year-old fossil unearthed in the Canadian Arctic that is considered to be an important evolutionary link between fish and humans.
“Locked in the soils and ice of the poles are clues to our past and things that will shape our planetary future.”
In his new book, Shubin brings the polar world to life through a combination of travel and immersive science writing. He takes the reader to Antarctica, Canada, Norway, and laboratories around the world, talking to scientists in fields ranging from paleoclimatology to geology to engineering. Along the way, Shubin explores the adaptations plants and animals needed to survive in harsh polar climates, what topographical changes can tell us about our world, and the stories the ice tells through meteorites embedded in it over millions of years. It’s also the story of polar exploration: the techniques and tools that have evolved and been fine-tuned over time, including those developed by Indigenous communities.
And finally, it’s the story of the environment itself, in particular the fragility of the poles and the profound changes to these landscapes due to global warming. Shubin writes, for example, about the impact of hundreds of wildfires that broke out in Siberia in 2021: “These so-called zombie fires were the rekindled remains of fires from the previous year,” he writes. “With carbon-rich peat underground, the fires had smoldered for months under the ice.”
Though the Arctic is usually free of thunderstorms and the lightning that can spark wildfires, “the incidents of summer lightning in the Arctic have tripled” since 2010, he writes. “In recent years, lightning even has struck within 60 miles of the North Pole.” The region’s increasing temperatures, it seems, are fueling more frequent and longer storms.
The first chapter, titled “ICE IS HOT,” takes its name from an explanation given to Shubin by Sridhar Anandakrishnan, a glacial expert, during an expedition to McMurdo Station in Antarctica. Water can be a solid, liquid, or gas on a fairly narrow temperature spectrum, he was told, and “because of the physics of the molecule, ice is hot in terms of the temperature required to melt it into a liquid,” especially compared to other materials, like steel. And because ice under high pressure melts at even lower temperatures, the bottom layer of a glacier “is right on the cusp of melting.”
The constantly changing nature of ice is a theme returned to repeatedly. Glacial ice can be more than one thing at a time in various places: part liquid, part solid; it can melt, bend, refreeze, and even act like a gel. It defies simple explanations, and Shubin notes that the Inuktitut language uses different combinations of words and phrases to describe various properties and characteristics of ice.
He explores the astonishing variety of plants, insects, and animals that have adapted to polar temperatures. Arthur DeVries, for example, a University of Illinois physiologist who worked at McMurdo Station in the 1960s, found a fascinating protein in the blood of icefish. This protein had a structure that could bind to ice crystals to prevent them from growing and damaging cells. When he and his colleagues sequenced the protein, they found it was almost identical to a digestive protein in the fish’s liver. “With a few small mutations over time, this liver protein was repurposed into an antifreeze in the ancestors of icefish,” he concluded. Since then, these kinds of “antifreeze compounds have been discovered in different fish, insects, plants, and fungi living in both the northern and southern polar regions.”
But the poles don’t only provide clues to life on Earth. Since the first meteorite was discovered in Antarctica in 1912, more than 50,000 others have been recovered from the Antarctic, providing a glimpse into the history of the universe: “These small meteorites hold the material that swirled around the sun prior to the formation of the planets and asteroids. The components of the meteorites reflect the brick and mortar of our part of the solar system, the basic ingredients that went into the making of our planet and others.”
Glacial ice can be more than one thing at a time in various places: part liquid, part solid; it can melt, bend, refreeze, and even act like a gel. It defies simple explanations.
It’s only toward the end that Shubin directly addresses the impact of global warming on polar regions. Permafrost, which is ground that is frozen or below freezing for at least two years, makes up approximately 15 percent of the Northern Hemisphere. When it melts, he notes, the results can be devastating: “Melting permafrost changes the landscape because liquid water takes up less volume than ice. When ice thaws, the ground above buckles and a crater can appear at the surface.” One such crater in Batagay, in far eastern Russia, started to form in the 1970s and is now nearly a half mile long and expanding by as much as 20 feet each year, Shubin writes.
Meanwhile, Arctic communities are learning to adapt as best they can ⏤ a strategy that includes relocation. Encroaching water and land erosion has already forced some Alaskan villages to undergo the complicated process of moving an entire town, made more complex by the remote location. The community of Newtok successfully lobbied the Federal Emergency Management Agency to secure federal funds to help establish a new village, Shubin writes, but constructing housing remains a challenge. In December 2024, with nearly 20 families living in temporary tiny houses at the new townsite, critical infrastructure in Newtok was turned off as the last of nearly 400 residents finished packing their belongings.
As Shubin demonstrates in “Ends of the Earth,” the stark polar regions present extreme challenges not only to humans, but to all living things. Yet, through adaptation, life finds a way. “Success and longevity in the polar world is something different altogether from life elsewhere,” Shubin reflects in the book’s last chapter. “It is a story of Survival of the Resilient.”
Jaime Herndon is a science writer and editor whose work has appeared in Book Riot, goEast/Eastern Mountain Sports, Healthline, and American Scientist, among other publications.
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