They were still around when the Great Pyramid of Giza was built
Woolly mammoths seem old-school. Hunted by Neanderthals for tens of thousands of years, these elephantlike mammals, some with tusks up to 15 feet long, evolved hair and layers of fat to withstand the frigid temperatures of the ice age tundra as they roamed the northern reaches of Asia, Europe, and North America. Although they're no longer among us, their bones — and in some cases mummified remains — fill natural history museums around the world. But these ancient beasts aren’t as ancient as you might think. In fact, it’s estimated that the last woolly mammoth died around 1700 BCE — some 800 years after ancient Egyptians built the Great Pyramid of Giza.
As the Earth began transitioning out of the last ice age some 12,000 years ago, a warming world altered the woolly mammoth’s ecosystem. Melting glaciers created a wetter planet that destroyed the vegetation mammoths relied on for food, and this dramatic shift — along with continued human predation — led to complete extinction of the creatures in most areas around 8000 BCE. However, small pockets survived on some islands that benefited from both cold-weather vegetation and protection from human hunters.
Some of the last known mammoths lived in isolation on Wrangel Island, a Russian possession in the Arctic Ocean just northwest of Alaska, and they didn’t have an easy go of it. Scientists who compared a 4,300-year-old mammoth bone from Wrangel Island to mammoth specimens 10 times older and from the Siberian mainland found that these final woolly mammoths experienced what scientists call a “genetic meltdown” due to the limited gene pool on the island, with mutations that likely made it harder to mark territory and choose mates. As for the ancient Egyptians, they kept chugging along until the death of Cleopatra, in 30 BCE. With its transformation into a Roman province, the 3,000-year-old dynasty also went the way of the woolly mammoth.
The woolly mammoth is a leading candidate for a controversial process known as “resurrection biology.”
What if scientists could bring an animal back from extinction? It’s a question famously explored in Michael Crichton’s 1990 science fiction novel Jurassic Park (and the subsequent movie adaptations), even if the answers there were less than encouraging. One problem in the fictional setup was that humans and dinosaurs are separated by 65 million years of evolution — but what if scientists brought back an animal that roamed the Earth alongside humans? That’s the question scientists are exploring with a process called de-extinction, also known as resurrection biology. Because it’s likely impossible to create an exact copy of an extinct animal, de-extinction aims to create “proxy” animals that fulfill the same ecological function. One plan is to alter the genome of elephants to create a cold-resistant, mammoth-elephant hybrid, or a mammophant. Biologists working on the project aren’t aiming to open an ice age-themed amusement park, but instead want to reintroduce the creatures to the tundra, where they can once again control arctic shrubs and trees while manuring the soil. In 2021, a de-extinction company called Colossal raised $15 million to bring back the woolly mammoth, and soon announced that calves could walk the Earth within a few years. Yet the idea remains controversial: Instead of working on de-extinction, some scientists want to leverage the gene-editing technology (and the funding that comes with it) to save the many vulnerable animals still struggling for survival today.
About 3700 years ago, as Mesopotamian poets were composing the "Epic of Gilgamesh," the last woolly mammoths on Earth were making their last stand on a remote Arctic island. A terminal colony persisted on tiny Wrangel Island north of the Siberian mainland thousands of years after the rest of its kind had disappeared. Now, a new study reveals the mammoths' horrific final days: A series of harmful genetic mutations appears to have led to what authors call a "genomic meltdown" in the population.
Woolly mammoths by the tens of thousands once roamed across ice age grasslands spanning Europe, Asia, and the northern reaches of North America. But after the global climate began warming some 12,000 years ago, mossy tundra began to replace grasses, depriving the massive animals—roughly the size of modern African elephants—of their most important food source. Human hunters further culled their numbers. Woolly mammoths went extinct on the mainland about 10,000 years ago, but small pocket populations persisted on islands, isolated from human contact.
Hoping to learn more about the last lonely days of the Wrangel Island mammoths, bioinformatics researcher Rebekah Rogers of the University of North Carolina in Charlotte and biologist Montgomery Slatkin of the University of California (UC), Berkeley, compared the complete DNA sequence from a 4300-year-old mammoth bone found on Wrangel Island with that of a 45,000-year-old specimen that lived on the Siberian mainland.
The researchers identified a series of major detrimental mutations in the Wrangel Island mammoth. One combination of altered genes likely led to the loss of a large number of olfactory receptors for detecting smells. Another suite of mutations would have reduced the number and variety of the animals' urinary proteins. Together, those changes would have wreaked havoc on the mammoths' ability to mark and recognize territory, determine rank, and choose mates, if—like modern mammals—they relied on odors for these tasks. The result for the Wrangel Island mammoth community, which numbered about 300 based on population genetics models, could have been social chaos, researchers report today in PLOS Genetics.
In another bizarre twist, two peculiar mutations to a gene known as FOXQ1—well studied in rodents and rabbits—would have given the Wrangel Island mammoths a translucent, cream-colored, satiny coat. The hairs of its fur would have lacked an inner core, possibly robbing them of their insulating properties. Mice with this mutation also suffer from gastric irritation.
Harmful mutations like these are predicted to build up in small, isolated populations that become inbred, a phenomenon called genomic meltdown, according to most evolutionary biologists. If your options for a mate are limited, you can't be too choosy about undesirable genetic traits, so those don't get weeded out. The Wrangel Island mammoths provide a rare opportunity to see that theory play out in a real population, Rogers says.
Though the study included only a single specimen from the island, Rogers is confident its genetics would closely match the island's other mammoths. That's because the number and types of differences between its genome and the older mainland mammoth snugly fit mathematical predictions for how much genetic variation should exist between two individuals from the same species over time.
Beth Shapiro, a paleogenomics researcher at UC Santa Cruz, who wasn't involved with the study, agrees. "I think it's a great example of what evolutionary theories would predict, but it's rare and great to see in a natural setting," she says.
It is unlikely that any single mutation doomed the Wrangel mammoths—it still isn't clear exactly what led to their eventual extinction. Rather, their
deteriorating genetics would have made it difficult for them to adapt to new social and environmental conditions, Rogers says. Shapiro sees it as a lesson for modern populations that are dwindling and isolated. "By the end, the Wrangel Island mammoths were genetically screwed. Understanding how that happened might help us figure out which species today are most at risk of the same thing happening."
Scientists want to resurrect the woolly mammoth. They just got $15 million to make it happen
By Katie Hunt, CNN
Published 4:50 PM EDT, Mon September 13, 2021
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Bringing extinct creatures back to life is the lifeblood of science fiction. At its most tantalizing, think Jurassic Park and its stable of dinosaurs.
Advances in genetics, however, are making resurrecting lost animals a tangible prospect. Scientists have already cloned endangered animalsand can sequence DNA extracted from the bonesand carcasses of long-dead, extinct animals.
Geneticists, led by Harvard Medical School’s George Church, aim to bring the woolly mammoth, which disappeared 4,000 years ago, back to life, imagining a future where the tusked ice age giant is restored to its natural habitat.
The efforts got a major boost on Monday with the announcement of a $15 million investment.
Proponents say bringing back the mammoth in an altered form could help restore the fragile Arctic tundra ecosystem, combat the climate crisis, and preserve the endangered Asian elephant, to whom the woolly mammoth is most closely related. However, it’s a bold plan fraught with ethical issues.
The goal isn’t to clone a mammoth – the DNA that scientists have managed to extract from woolly mammoth remains frozen in permafrost is far too fragmented and degraded – but to create, through genetic engineering, a living, walking elephant-mammoth hybrid that would be visually indistinguishable from its extinct forerunner.
“Our goal is to have our first calves in the next four to six years,” said tech entrepreneur Ben Lamm, who with Church has cofounded Colossal, a bioscience and genetics company to back the project.
‘Now we can actually do it’
The new investment and focus brought by Lamm and his investors marks a major step forward, said Church, the Robert Winthrop Professor of Genetics at Harvard Medical School.
Up until 2021, it has been kind of a backburner project, frankly. … but now we can actually do it,” Church said.
“This is going to change everything.”
Church has been at the cutting edge of genomics, including the use of CRISPR, the revolutionary gene editing tool that has been described as rewriting the code of life, to alter the characteristics of living species. His work creating pigs whose organs are compatible with the human body means a kidney for a patient in desperate need of a transplant might one day come from a swine.
“We had to make a lot of (genetic) changes, 42 so far to make them human compatible. And in that case we have very healthy pigs that are breeding and donating organs for preclinical trials at Massachusetts General Hospital,” he said.
“With the elephant, it’s a different goal but it’s a similar number of changes.”
This animal survived 24,000 years frozen in the Siberian permafrost
The research team has analyzed the genomes of 23 living elephant species and extinct mammoths, Church said. The scientists believe they will need to simultaneously program “upward of 50 changes” to the genetic code of the Asian elephant to give it the traits necessary to survive and thrive in the Arctic.
These traits, Church said, include a 10-centimeter layer of insulating fat, five different kinds of shaggy hair including some that is up to a meter long, and smaller ears that will help the hybrid tolerate the cold. The team also plans to try to engineer the animal to not have any tusks so they won’t be a target for ivory poachers.
Once a cell with these and other traits has successfully been programmed, Church plans to use an artificial womb to make the step from embryo to baby – something that takes 22 months for living elephants. However, this technology is far from nailed down, and Church said they hadn’t ruled out using live elephants as surrogates.
“The editing, I think, is going to go smoothly. We’ve got a lot of experience with that, I think, making the artificial wombs is not guaranteed. It’s one of the few things that is not pure engineering, there’s maybe a tiny bit of science in there as well, which always increases uncertainty and delivery time,” he said.
Skepticism
Love Dalén, professor of evolutionary genetics at the Centre for Palaeogenetics in Stockholm who works on mammoth evolution, believes there is scientific value in the work being undertaken by Church and his team, particularly when it comes to conservation of endangered species that have genetic diseases or a lack of genetic variation as result of inbreeding.
“If endangered species have lost genes that are important to them … the ability to put them back in the endangered species, that might prove really important,” said Dalén, who is not involved in the project.
“I still wonder what the bigger point would be. First of all, you’re not going to get a mammoth. It’s a hairy elephant with some fat deposits.
“We, of course, have very little clue about what genes make a mammoth a mammoth. We know a little, bit but we certainly don’t know anywhere near enough.”
A perfectly preserved cave lion cub found frozen in Siberia is 28,000 is years old. Even its whiskers are intact.
Others say it’s unethical to use living elephants as surrogates to give birth to a genetically engineered animal. Dalén described mammoths and Asian elephants as being as different as humans and chimpanzees.
“Let’s say it works, and there’s no horrible consequences. No surrogate elephant moms die,” said Tori Herridge, an evolutionary biologist and mammoth specialist at the Natural History Museum in London, who is not involved in the project.
“The idea that by bringing mammoths back and by placing them into the Arctic, you engineer the Arctic to become a better place for carbon storage. That aspect I have number of issues with.”
Some believe large that, before their extinction, grazing animals like mammoths, horses and bison maintained the grasslands in our planet’s northern reaches and kept the earth frozen underneath by tramping down the grass, knocking down trees and compacting snow. Reintroducing mammoths and other large mammals to these places will help revitalize these environments and slow down permafrost thaw and the release of carbon.
Mammoths were the original 'ice road truckers,' traveling vast distances across the Arctic
However, both Dalén and Herridige said there was no evidence to back up this hypothesis, and it was hard to imagine herds of cold-adapted elephants making any impact on an environment that’s grappling with wild fires, riddled with mires and warming faster than anywhere else in the world.
“There’s absolutely nothing that says that putting mammoths out there will have any, any effect on climate change whatsoever,” Dalén said.
Ultimately, the stated end goal of herds of roaming mammoths as ecosystem engineers may not matter, and neither Herridge nor Dalén knock Church and Lamm for embarking on the project. Many people might be happy to pay to get up close to a proxy mammoth.
“Maybe it’s fun to showcase them in the zoo. I don’t have a big problem with that if they want to put them in a park somewhere and, you know, make kids more interested in the past,” Dalén said.
There is “zero pressure” for the project to make money, Lamm said. He is banking on the endeavor resulting in innovations that have applications in biotechnology and health care. He compared it to how the Apollo project got people caring about space exploration but also resulted in a lot of incredible technology, including GPS.
“I am absolutely fascinated by this. I’m drawn to people who are technologically adventurous and it is possible it will make a positive difference,” Herridge, the mammoth expert, said.
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