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Kindle Notes & Highlights
by
Neil Shubin
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August 24 - October 29, 2025
If life can thrive under the ice in Antarctica on eroded rock and water, perhaps it can do so in extraterrestrial environments. The work in Antarctica not only reveals how microbes can survive in surprising places, it prompts scientists to devise the technologies that could probe distant moons.
In 2002 our camp was hit by a large gale with sustained winds over 70 miles per hour and gusts even higher. At the height of the storm, two of our tents began to shred on their windward sides. For several hours we scrambled among the tents in raging winds to secure them and the gear inside. We managed to move between the tents by taking oblique angles to avoid walking directly into the teeth of the winds. On occasion, surprisingly large gusts came out of nowhere and threw all four of the crew to the ground simultaneously—nature’s way of telling us to be quadrupedal rather than bipedal.
Being on the ground during the storm was a revelation; it felt like an oasis from the ferocity above. At the heart of the gale, this place was quiet and still. Here, life continued uninterrupted. Spiders crawled along the mosses, bees flew low among wildflowers, and caterpillars fed on other low-lying plants. This windless world is also warm because it radiates the heat absorbed during twenty-four hours of sunlight in the summer.
As temperatures begin to drop, the woolly bear does its biological magic—it freezes to become a solid hairy cylinder. When temperatures rise and snow melts the following June, the woolly bear thaws and emerges to begin feeding, basking in the sun’s heat, and storing energy. The cycle repeats when the woolly bear freezes again in the fall. Ecologists who have looked at the growth rates of the woolly bear estimate that it lives in this freeze-thaw cycle for at least seven years, and possibly as many as fifteen.
Each year the woolly bear stores ever more energy, until the summer it has accumulated enough resources to transform into a moth. The moth flies for two weeks, finds a mate, expends its accumulated energy stores, and dies. Nearly a decade of freezing and thawing, feeding, and basking, all the while avoiding predators, is all in the service of two weeks of flying and mating.
When tissue freezes, the water inside it forms ice. Ice has a greater volume than water, so as it expands, cells burst. Almost as bad as freezing is thawing. When frozen tissues melt, cells deform and their fluids can tear through the membranes around the cells. The thaw is the most damaging part of frostbite in humans for this reason.
The hospital staff couldn’t find a pulse either, and their EKG also showed no heart activity. Knowing the body’s responses to the cold, they hooked Anna up to a heart-lung machine to give her oxygen and gradually warm her blood. After one day, her heart was able to beat on its own. After twelve days, she opened her eyes. It took another year for her to be able to move because of damage to her nerves. Bågenholm is now a practicing radiologist working in the same hospital that revived her. The lead doctor on Bågenholm’s case later quoted a famous truism about hypothermia: “You’re not dead until
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The antifreeze story got more interesting when DeVries and his colleagues sequenced the protein and compared it with other proteins. 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.
antifreeze compounds have been discovered in different fish, insects, plants, and fungi living in both the northern and southern polar regions.
Industries have taken an interest in these natural antifreeze proteins. Imagine having an ice cream that doesn’t form ice crystals after months in a freezer. Unilever attempted to manufacture just that in 2007. They took the gene that makes the antifreeze protein in an Antarctic eel and genetically modified it to make it in industrial quantities to put into their ice cream, code named “VanEELa.” Obviously, the marketing department did not coin the moniker and the product never made it to the shelves.
Antifreeze is not the only means to avoid the cellular damage of extreme cold and ice-crystal formation. Another mechanism is to just get rid of the water in the body altogether—with no water, there is no freeze-thaw damage. Many invertebrate animals desiccate in the extreme cold and dry conditions of Antarctica.
Musk oxen look, as the name implies, like large bovine creatures with a coat of hair that extends almost to the ground. In reality, their closest relatives are not oxen, but goats. Shave a musk ox and you see a naked goat with shorter legs and broader horns.
The legs of seabirds in polar regions extend into frigid waters that are often below standard freezing temperatures. These creatures use their circulatory systems to retain heat inside the body. The arteries that run from the legs to the feet are bundled in parallel to the veins that return the blood to the body. The heat in the arteries is picked up by the colder veins that return blood to the animal’s core. This means that the warmth of the blood in the arteries stays in the body and does not dissipate into the environment. With this neat trick, little heat is lost.
A corollary to this rule is that the longer the limbs, the greater the potential for heat loss. Limbs project from the body and are exposed to the elements. Longer limbs mean an animal has a greater surface area than one with shorter limbs. Consequently, polar animals tend to have shorter appendages than those that live closer to the equator.
Looking for fossils in polar terrain means being sensitive to changes in texture and color of the landscape. Fossils typically stand out because they are a different tint or shape from the rocks we typically encounter.
Many of our uniquely human characteristics came about as adaptations to the warm, subtropical environments of East African rift valleys. In that region, our human ancestors developed a nomadic, bipedal lifestyle. Large brains supported increasing cognitive abilities with ever more complex tools and, likely, social interactions. The problem is this: our brains only function within a narrow window of temperatures.
managing heat in the savannah was the name of the game for our ancestors. To stay cool, they lost a hairy coat of insulation and evolved an enormous number of sweat glands in the skin—more than any other mammal.
Human history near the poles begins in Siberia 40,000 years ago. Later, around 4,000 years ago, Inuit traditions and technologies allowed populations to live nomadic existences in the far north.
Inuit health has long been a paradox for Western medical researchers. By necessity, the traditional diet is low in fruits and vegetables and high in fats derived from seals, whales, and other marine animals. Given their fatty diet it would be expected that Inuit would suffer from cardiac conditions, such as atherosclerosis, that cause suffering in people farther south. But that is not the case. Inuit heart health exceeds that of most European, Han Chinese, and North American populations that have been studied.
100 percent of the Greenlandic people tested had a combination of genetic variants that were found in only 2 percent of Europeans and Han Chinese. These genetic adaptations play a very specific role in the body—they are involved in the metabolism of the kinds of fats found in marine mammals. Known as desaturases, these enzymes convert saturated fats to unsaturated ones.
These experimental results are in line with observations of human populations—people who experience cold tend to have a greater percentage of brown fat than those who do not. In fact, recent work suggests that cells in our body respond to different temperatures to produce different types of fat. Cold can directly induce stem cells throughout our bodies to make more brown fat than white.
Recent experiments suggest that Bowers’s frigid routine was no mere boast—we can become desensitized to the cold. When experimental volunteers are subjected to different regimens of cold, whether being put in a cold pool for a period or in a cold room, their responses will change. Over time, people acclimating to the cold shiver less and their vessels do not shunt blood as much as before at the same frigid temperature.
Arguably, the most essential part of stressful work in uncertain conditions is ensuring that people feel valued, heard, and that their well-being is a priority for the expedition. Ernest Shackleton was affectionately nicknamed “The Boss” by his crew, because they knew he would suffer any privation for their safety and for the success of their group effort. And he did just that when he rescued the crew of the Endurance in 1916 from South Georgia Island.
layers of clothing must follow specific patterns. The closest layer to your body should wick away perspiration. Cotton is particularly bad at diffusing sweat; wool and various synthetics are ideal. On top of this layer, middle ones hold insulation, while the outermost layers protect from wind and moisture.
We picked up a meteorite approximately 5" 3" 3.5" covered with a black scale, internally of a crystalise [sic] structure, most of the surface rounded except in one place which looks like a fracture, iron is evidently present in it. It was lying about 2.5" below the mean surface and did not appear to have been there long, probably only a month or so.
Mawson was near death when he encountered Bickerton upon his return. What had killed Mertz and nearly claimed Mawson was the dog meat. They had eaten every soft part of the dogs, including the liver. The livers of the huskies were so enriched in vitamin A that both men suffered from vitamin A poisoning. Mertz did not like the tough muscle meat and ate more of the liver than Mawson did. Hence the different fates of the two men.
Perhaps there was something about moving ice that concentrated the meteorites that fell on it? The Japanese team proposed that the blue ice of Antarctica was special, that its movements caused meteorites that landed on it to be preserved on and in it, and that in some places the movements of the ice concentrated them.
The program Cassidy launched, the Antarctic Search for Meteorites (known by the acronym ANSMET), has been running continuously since 1976, training hundreds of researchers. More than 50,000 meteorites have been recovered as of last count.
The equation discovered by the Japanese researchers, Cassidy, and his team is a simple one: ice movement + barriers = the potential to find meteorites.
The most common kind of meteorite, one that makes up 94 percent of the entire collection, is of the type that Bickerton picked up in 1912. The black fusion crust surrounds a grayish interior composed of grains the size of beach sand. Between the grains are small inclusions, known as chondrules,
Atomic dating suggests these kinds of meteorites are 4.56 billion years old—almost a million years older than Earth. The grains and chondrules appear relatively undeformed by heat or pressure, as only the external surfaces are blistered and melted by their entry into the atmosphere. These small meteorites hold the material that swirled around the sun prior to the formation of the planets and asteroids.
Meteorites containing chondrules.
Did they come from one of the other planets, like Mercury, Venus, or Mars? If so, how? In 1979, Bill Cassidy led the ANSMET team to a small mountain on the Antarctic ice called Elephant Nunatak (“nunatak” is the geographic term for a mountain that pokes through the ice).
Meteorites that were younger than earth and the moon.
When they compared the gases released from the glass inside the meteorite to the atmosphere of Mars, they found the gases were identical. EETA79001 was a chunk of Mars, blasted off by an asteroid impact, only to fly into space and enter Earth’s atmosphere. Even the chemistry of the Martian atmosphere was preserved inside its atoms.
Think of the odds of an asteroid hitting Mars, spalling off a rock that gets caught by the Earth’s gravitational pull and lands on Earth in the exact spot the hound was walking in Egypt at nine a.m. on June 28, 1911. Very, very, small.
While there is no definitive evidence of life in ALH84001, that doesn’t mean the interpretation is wrong. We simply do not have enough data to contradict the original hypothesis that fossil life is present. As Everett Gibson from the Johnson Space Center said in 2006, on the twentieth anniversary of the announcement, “Despite whether you are a believer of the hypothesis or not, it has clearly been the guiding idea for the development of the new interdisciplinary field of astrobiology.”
Meteorite from Mars.
By some estimates, as much as 60,000 tons of debris from the solar system rain down each year. That large mass dwarfs that of meteorite falls—a mere 50 tons of meteorites might land on Earth in the same interval of time.
Our world is full of dust of all kinds, from exhaust to the debris of human activity, and finding places where the cosmic dust is in pristine shape can be a challenge. But there’s one obvious candidate: Antarctica. Its remoteness from all ordinary human activities, and its continent-sized sheet of pure ice, has made it a natural laboratory for scientists to collect and study stardust.
The team was surprised to find a strange element in the ice: iron 60. This version of iron is produced in only two known places. It is the product of nuclear reactions such as those that occur in reactors. The scientists knew, given the prevailing winds, and the great distance between any nuclear reactors and the Kohnen Station, that a nuclear plant was not the source. The only remaining possibility was that the iron 60 came from a large supernova in outer space.
Currently, the solar system has entered a vast field of space known as the Local Interstellar Cloud. This field, about 300 light-years across, is a field of dust created by a star that exploded eons ago. The solar system moves about 50 miles per second through this field and, like a convertible car with the top down, the field’s dust enters our orbit each day.
The South Pole Telescope is designed to measure the oldest light in the universe, dating back to just 380,000 years after the Big Bang,
Because of the clarity of the South Pole location, the telescope there can make measurements of the cosmic microwave background that are sharper and at a higher resolution than anywhere else on Earth. These discoveries reveal the hidden structure of the universe, one we cannot see with visible light. Differences in density of the signal can show the nature of mysterious dark energy and dark matter.
By measuring how the cosmic microwave background gets distorted or deflected at a very fine scale, astrophysicists can infer how patches of dark matter warp space in different parts of the sky.
Canada’s Ellesmere Island to study polar geography, natural history, and climate in 1902. The smashed crates we encountered that July day in 2000 were from when the Fram explored our fiord during the 1902 expedition. We imagined that the crates had likely held supplies.
For me, the smallest discovery made by the Fram’s team was the most significant. As the Fram probed into what eventually became the Canadian Arctic islands, the youngest scientist on board, the ship’s natural historian, found tiny fish scales inside the rocks of one of the fiords. These were from the extinct fish species that my colleagues and I were finding fossils of in the same fiord nearly a hundred years later.
Barents was of the opinion that twenty-four hours of continual daylight in the extreme north should make summer temperatures too warm for permanent ice, even at the North Pole. Further reducing the presence of ice, he surmised, was the saltiness of the sea, which chemically lowers the temperature at which ice forms. Together, these ideas led to the influential theory that an entire ocean extended, uninterrupted, from Alaska to Greenland and Siberia. This dream of an ice-free pole, known as the Open Polar Sea,
William Barents, born in 1550, was a Dutch navigator and cartographer. . .
The names of Barents, Baffin, Hudson, Frobisher, Scoresby, Ross, Melville, and Franklin—all explorers who tried to push to the farthest north or find an ice-free passage between oceans—are now scattered across the maps of bays, islands, and mountain ranges of the Arctic. And while the expeditions were outfitted by males, some of the most lasting contributions to polar science were made by a woman, Lady Jane Franklin.
According to an apocryphal tale, the first person to set sights on the Antarctic Circle was the seventh-century Polynesian navigator Ui-te-Rangiora.
The first recorded sighting of the continent was by a Russian expedition led by Fabian Gottlieb von Bellingshausen in 1820. Within ten months of Bellingshausen, British and American ships also sighted the continent, and claims of first discovery have been controversial ever since.
The challenge of reaching the South Pole is that it is not only extraordinarily cold, but that it lies at an altitude 9,200 feet above sea level.
The entire trip is perilous at any altitude because of near constant wind and ice that is roiling with hummocks and crevasses for hundreds of miles.
