Mammoths
Mammoths were large, elephant-like mammals that roamed the Earth during the Pleistocene epoch, particularly favored in cold tundra and grassland habitats. They are classified within the order Proboscidea and include several species, such as the well-known woolly mammoth and various dwarf varieties. Standing between 3.5 and 4.3 meters tall, mammoths were characterized by their long, curved tusks, thick fur, and substantial fat layers, which allowed them to thrive in harsh climates. They primarily lived in herds and exhibited social behaviors, including protective instincts toward their young and elderly members.
Fossil evidence shows that mammoths became extinct around 13,000 to 2000 BCE, with factors such as climate change and human hunting being possible contributors to their decline. Ongoing paleontological discoveries, particularly in regions like Siberia and North America, have yielded remarkably preserved specimens, offering insights into their biology and environment. In recent years, scientific efforts have focused on the potential revival of woolly mammoths through advanced genetic engineering, which has sparked significant debate and research into creating mammoth-elephant hybrids. The fascination with mammoths continues to inspire both scientific inquiry and public interest, reflecting their enduring legacy as iconic creatures of the prehistoric world.
Mammoths
Mammoth Facts
Classification:
Kingdom: Animalia
Subkingdom: Metazoa
Phylum: Vertebrata
Class: Mammalia
Subclass: Eutheria
Order: Proboscidea
Suborder: Elephantoidea (elephant-like)
Family: Elephantidae
Genus and species: Mammuthus africanavus (North African), M. columbi (Columbian), M. creticus (Cretan dwarf), M. exilis (dwarf), M. imperator (North American), M. jeffersonii (southern North America), M. meridionalis (European), M. primigenius (wooly), M. subplanifrons (southeast Africa), M. trogontherii (steppe mammoth)
Geographical location: Africa, Northern Europe, North America, Eurasia, Siberia
Habitat: Tundra, grasslands
Gestational period: Twenty-two months
Life span: Sixty years
Special anatomy: Curved tusks, fatty hump, protruding brow
Mammoths lived during the Ice Ages of the Pleistocene epoch. The oldest recovered mammoth fossils, found in Africa, are four million years old. Mammoths migrated from Africa, and several species of varying sizes and appearances evolved on other continents. Some mammoths crossed the Bering land bridge. Most mammoths favored tundra habitats formed when Ice Age glaciers covered parts of the northern hemisphere.
Anatomy
Most mammoths were large mammals, standing 3.5 to 4.3 meters (12 to 14 feet) tall when measured from the ground to the top of their shoulders. They weighed an average of seven metric tons (eight tons). Other mammoths were dwarves that only stood 1.8 meters (6 feet) tall. These small mammoths lived on islands, including Siberia’s Wrangel Island and California’s Channel Islands.
Woolly mammoths grew long, thick brown fur over a short undercoat, which protected them in cold climates. Fat layers, which were 7.5 centimeters (3 inches) thick, underneath their skin and in their shoulder hump and prominent brow, insulated their bodies. Each mammoth had two ivory tusks, which extended from their upper jaw. Mammoths’ tusks were as long as five meters (sixteen feet) and curved toward and crossed over their trunk. During their lifespan, they had a total of twenty-four molars, which they shed. Because of their cold habitat, mammoths’ ears were small, to retain heat. Mammoths had domed heads, sloping backs, and a short tail.
Life Cycle
Mammoths roamed in herds, sometimes covering great distances in their search for vegetation, such as sedge and Arctic sagebrush, to eat. They spent an average of twenty hours a day finding and eating food. Chewing plants smoothed their teeth. When frozen land inhibited plant growth, the mammoths’ stored fat provided essential nutrients and vitamins necessary to live.
Mammoths acted protectively toward immature, elderly, and infirm herd members. Males often fought over females during breeding seasons. Gestation lasted twenty-two months. Females usually produced one calf. Mammoths were unique because their mammary glands were near their front legs, unlike other mammals. Young mammoths remained with their mothers for several years, gradually becoming independent. Mammoths reached maturity by the age of twelve years.
Because of their size, adult mammoths had few predators. They moved slowly, which made them more vulnerable. The saber-tooth tiger killed mammoths for their flesh, and prehistoric humans hunted mammoths for their meat, hides, bones, and tusks. Human hunters devised strategies to capture mammoths in traps that confined their legs. Prehistoric people used mammoth tusks and bones to build shelters. Many mammoths died when they fell into naturally occurring sinkholes or were mired by quicksand and tarpits. Sometimes, male mammoths’ tusks became entangled while fighting, and they starved to death.
Although mammoths were abundant during the Ice Ages, they became extinct in the period between 13,000 and 2000 BCE Paleontologists estimate that the last mammoths died circa 1800 BCE. Researchers hypothesize that mammoths’ extinction occurred because they were unable to adapt to the altered environment, specifically the warmer climate and different edible plants that existed after the final Ice Age, or that humans hunted them into extinction. Evidence exists for both theories. Mammoths migrated north as glaciers began to recede. When the final Ice Age glaciers disappeared about 9500 BCE, many placental mammals became extinct. Fossils suggest that some mammoths survived on an isolated Siberian Arctic island until 1500 BCE.
Recovering Specimens
Humans have found mammoth fossils on land and in bodies of water, such as the North Sea, which used to be dry land where mammoths roamed. The Siberian permafrost has preserved carcasses that have not decomposed or become too dry for examination. A baby mammoth that scientists called Dima was located in 1977 and had intact red blood cells. Many mammoth fossils have been located during the digging of the Eastside Reservoir, near Los Angeles, California, including a female found in April 1999, which is considered to be the best preserved mammoth specimen.
In 2000, paleontologists recovered what they believed to be the first completely frozen mammoth on Siberia’s Taimyr Peninsula. Named the Jarkov mammoth, it was airlifted to a cold cave research facility, encased in a block of permafrost that included plants, insects, and pathogens, which scientists hoped would provide insights to mammoths’ environments. They planned to test a hypothesis that mammoths became extinct due to an epidemic. Initially, scientists hoped to secure enough DNA to clone the mammoth, but it turned out that radar readings had incorrectly shown more of the carcass remaining than actually existed.
When crews began digging to extend a subway line in Los Angeles, California, around 2014, they began finding a wide array of preserved bones belonging to animals that had lived largely during the final Ice Age. In late 2016, the intact fossil of a junior mammoth's skull was discovered at the site. The fossil, estimated to be more than ten thousand years old, was named Hayden and was brought to a preservation lab for further study and eventual display. In 2022, gold miners in Yukon's Klondike region of Canada found a mummfied whole baby woolly mammoth, only the second whole mammoth ever found.
Reviving Woolly Mammoths
The idea of reviving the woolly mammoth was widely debated in the late 2010s. While some scientists have argued that cloning by replacing the nucleus of a female elephant egg cell with the nucleus of a mammoth cell could revive the woolly mammoth species, other scientists state that a pure woolly mammoth cannot be recreated. Instead, many scientists are focused on creating a mammoth-elephant hybrid.
In 2015, scientists in Sweden published the complete genome of the woolly mammoth. That publication led several groups, including geneticist George M. Church and the Long Now Foundation, to begin experimenting by replacing the genes in an elephant cell with mammoth genes with the end goal of creating a mammoth-elephant hybrid. By 2017, Church's team had successfully made forty-five mammoth gene substitutions to the Asian elephant genome. Other projects, including the Mammoth Genome Project at Pennsylvania State University, took a similar approach by researching the modification of African elephant DNA. The group's goal was to create a hybrid embryo, which could then be implanted in a female elephant.
In 2021, Church and several other scientists and entrepreneurs launched the company Colossal, with a goal of repopulating the Siberian tundra with mammoth-elephant hybrids. The company received $15 million in initial funding to continue Church's research into gene editing. By 2023, the company continued its success. Though the company's focus remained on the mammoth, some argued that the technology Colossal created in the process of reviving the mammoth is more valuable—and draws in more investors—than the project's focus. Some advancements include artificial wombs, stem cell lines, and computational biology software. In 2024, Church confirmed that the project had made a colossal step forward in the revival of the mammoth. The heads of the biological science team, Church and Eriona Hysolli, had reprogrammed cells from an Asian elephant into an embryonic state. This marked a first in science, as stem cells had never previously been derived from elephant cells. The team planned to publish their work and take on the next step of using the cells to attempt to grow elephant cells.
Principal Terms
Ivory: A white or honey-colored, bony substance
Pathogens: Bacterium or viruses that cause diseases
Permafrost: Soil layer below the earth’s surface that never thaws
Pleistocene: Epoch occurring from 1.7 million to 10,000 years ago
Tundra: Vast, mostly treeless area coated by ice and snow
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