Beneath the surface of the North Sea, a graveyard from another chapter of the Earth’s history lies hidden under the freezing water. Amidst the remains scattered across the ocean floor are Ice Age era megafauna, and the hunting tools humans used to fell these giant beasts. This is Doggerland, a region that once connected England to Europe. During the Pleistocene epoch, lower sea levels spurred by the Ice Age connected the two landmasses. Bounded to the north by steep walls of ice, Doggerland was home to a steppe ecosystem full of life.
📸 A mammoth skull recovered from the North Sea.
This sunken strip of land was once a connection between Great Britain and the rest of Europe. During its heyday, Doggerland was rich with marshlands, rivers, and lagoons. This meant its ecosystem was filled with life and even people. 12,000 years ago, it may have been the best place in Europe for an early human to get a meal. However, as the Last Glacial Maximum ended, the sea levels rose and covered Doggerland, burying what was left below the waves. The name for this land is borrowed from the Dogger Bank, a large sandbank that rises 20m (66ft) from the seafloor and extends over 17,600 square kilometers (6,800 square miles).
In the popular imagination, the "Ice Age" happened in the distant past, but in fact, the ice age is still ongoing today. We just live in a warm pocket known as an interglacial period, also known as the Holocene. Our ice age began 2.6 million years ago at the start of the Pleistocene epoch. Repeated periods of glacial incursions during the Pleistocene created the permanent ice sheets that cover Antarctica, Greenland, and parts of the Arctic. The changing environment also allowed for the development of large animals known as megafauna specially adapted to the climate, including Mammuthus primigenius, better known as the woolly mammoth.
📸 Two woolly mammoths, with their shaggy hair for protection against the frigid cold.
A full-grown woolly mammoth, just one species of the genus Mammuthus, stood 10-12 feet at the shoulder with shaggy hair. This hair provided a substantial advantage in the struggle to stay warm. Roughly the mass of a modern African elephant, the woolly mammoth evolved some 400,000 years ago in Siberia from the steppe mammoth widespread on that continent, and ultimately spread westward into Europe and eastward into North America via the Beringian land bridge that once connected modern-day Russia and Alaska.
This event may have been the second mammoth migration of the New World, as the steppe mammoth forayed into North America about 1.5 million years ago and evolved there into the endemic (and enormous) Columbian mammoth. Mammoths were an important food source to early humans and neanderthals. They even used their bones and hides to create huts and other structures. Along with a shifting climate, it was this predation by humans that would ultimately drive the mammoth into extinction.
In Pleistocene North America, woolly mammoths primarily roamed the cold, treeless tundra-grasslands immediately below the continental ice sheets—the American reach of the mammoth steppe—while Columbian mammoths occupied a more southerly, temperate range encompassing most of today's Lower 48 States and which extended deep into Mexico. After disappearing from continental ranges roughly 10,000 years ago, small, isolated populations of woolly mammoth survived on Alaska's St. Paul Island until about 5,600 years ago and on Russia's Wrangel Island until perhaps 4,000 years ago. All of these pockets eventually died out due to the lack of genetic diversity that comes from metropolitan interactions with larger populations.
📸 An incredible tuft of mammoth hair
Our understanding of the Woolly Mammoth's appearance is extremely complete compared to other prehistoric creatures. This is due in part to fantastically preserved specimens found in permafrost.
Unlike dinosaurs, which have only left behind fossils of bones and faint impressions of skin and feathers, we have access to real samples of mammoth fur and meat. Creatures that died tens of thousands of years ago were locked within eternally icy areas which essentially acted as natural refrigerators. This kept their mummified bodies relatively fresh, allowing for collection and study of incredible tufts of hair and even musculature.
That said, they certainly are not fresh enough to eat. There are tales of a 1900 expedition, during which scientists uncovered a mammoth and dined on it. In reality, one brave soul tried to take a bite of the meat, but was not able to finish—it was a few thousand years past the expiration date.
📸 Now that's a tooth! (Mammoth ridged molar)
Mammoth’s high-crowned molars were pleated with ridges of enamel, somewhat similar to the dentition of the modern Asian elephant, but distinct from the fewer, diamond-shaped, enamel plates of the African elephant. The morphology of mammoth teeth and the distribution of mammoth remains suggests mammoths were predominantly grazers subsisting mainly upon grasses and sedges, a diverse biomass that the modern Arctic tundra does not approach.
These massive molars were set into huge jaws and helped the animals grind down and chew all sorts of plant material. The tough ridges were resistant to wear and tear from grit, so a mammoth would not have to be too picky about what food to eat. This is a very important adaptation for an animal so big—an adult mammoth likely needed to eat over 300 pounds of food each day and spent most of its time foraging.
📸 Blue Vivianite in a woolly mammoth tooth
Some woolly mammoth teeth have been discovered with a uniquely blue coloring to them. This stunning shade is due to vivianite implantations, a mineral formed by the combination of animal phosphorous and iron in the soil. Vivianite is usually pale or colorless when it forms, but when it is exposed to air the oxidation causes it to turn to a brilliant blue. In the right conditions, this process can produce incredible streaks of dark to light blue coloring in mammoth teeth, which is an incredible reminder as to the deep history of the fossil.
Interestingly, this can also occur on the skin of a well perserved animal as well. In fact, some ancient bisons have been found in the ice with blue coatings over their horns and bodies. It reminds us of the other famous blue megafauna we know: Babe the Big Blue Ox!
📸 A carbon dating chart used to pinpoint the age of a mammoth specimen.
Because many woolly mammoth specimens are younger than 50,000 years, scientists are able to date the remains to a very narrow window of time. They do this through carbon dating, which tracks the decay of Carbon-14 in organic material to give a near-exact date of death. Older material that has had its carbon isotopes dissipate completely is not suitable for this method, but for younger mammoths and other contemporaneous fauna, we have a clearer idea of when and how these organisms lived.
For example, a mammoth specimen in our collection that was found near Russia’s Indigirka river was dated to around 19,551 years old. The sample was calibrated against another mammoth dated to 17,501 years ago. From there you get a high and low range with multiple passes with different confidence levels. The higher confidence level pegs it to 19,551 years old with roughly 98% probability (matching curves on both axis). It is possible that the Indigirka sample is a thousand years younger based on the testing but since the curves match closely the older date is more probable.
📸 A woolly mammoth skeleton, on display at Tennessee's Discovery Park of America.
For years now, the possibility of cloning woolly mammoths has been a bit of a hot button topic in the scientific community. The abundance of biological material preserved from the Pleistocene epoch and the existence of close living relatives means this question is not entirely out of the realm of possibility.
There has even been the idea of a "Pleistocene Park," though with a greater purpose than the tourism suggested by its namesake. Russian geologist Sergey Zimov wants to bring these creatures back to the Siberian tundra. Why? To save the permafrost.
The theory is that by bringing a massive, climate adapted herbivore to the tundra, it will be able to flatten the ground and eat trees and shrubs. This would reinvigorate the grassland environment and leave more surface area to be cooled during the winter, helping prevent further melting of permafrost. The mammoth might just be the perfect candidate for the job—considering this is exactly what it did thousands of years ago.
For now though, cloning a woolly mammoth remains matter of speculation. Were a woolly mammoth ever to be recreated, it would find itself in a very foreign world. Even in a similar environment to its original time, many of its evolutionary adaptations would still be out of place. The woolly mammoth, with its thick hair and hide for protection from cold, and its ridged teeth for foraging, was perfectly suited to its period of the Earth’s history, a window which may be closed forever.
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