Imagine heading into the Siberian wilderness to see a furry mammoth leisurely pacing in its natural habitat, or get up close to a living Tasmanian tiger (a striped, dog-like marsupial, also known as a thylacine).
Thanks to developments in cloning and gene-editing, the prospects for resurrecting extinct species are more optimistic than ever.
Resurrecting extinct species refers to the creation of healthy and genetically viable animal populations that can reproduce naturally in the wild and make a positive contribution to the environment. But this science isn't just for reviving the dead, it can also be used to save endangered species.
So, what is the principle of resurrecting extinct species? And what are the limitations? Do we really have to bring a long-extinct species back to life?
<h1 class="pgc-h-arrow-right" >01 How feasible is it to resurrect extinct species? </h1>
Resurrecting extinct species is a science in progress, but it is evolving rapidly. In 2003, European scientists resurrected a Pyrenees goat that went extinct a few years earlier, achieving the first milestone.
Sadly, the sheep died a few minutes after it was born. Thus, the poor Pyrenees goat was not only the first species to be resurrected after extinction, but also the first to go extinct twice. Since then, scientists have been refining their methods and developing new techniques to resurrect extinct species.
The Pyrenees goat became the first species to go extinct twice
In Australia, Michael M. Professor Michael Archer and his colleagues are working to revive the stomach brooding frog. The peculiarity of this animal is that the mother frog hatches eggs in the stomach, feeds the young frogs, and does not spit them out until the frogs are mature.
So far, the team has grown embryos that can almost turn into tadpoles, but this has not yet been fully realized. The next step was to grow these embryos into frogs, something Archer was convinced they could do.
The gastric brook frog became extinct in the 1980s
In the United States, scientists are working to revive the North American passenger pigeon, whose chest was rose-colored, once hundreds of millions, and the stocky black grouse, which once lived on the grassy plains of New England. In the UK, researchers are considering whether to resurrect the so-called "Arctic penguins," the great auk.
In South Africa, researchers are trying to revive the White Zebra, a strange animal that looks exactly like a zebra but has no stripes on its back. In South Korea, Japan and the United States, three independent research teams are racing to revive the ice age's most iconic beast, the mammoth.
The extinct White zebra, which resembles a zebra, has only stripes on its head and shoulders
<h1 class="pgc-h-arrow-right" >02 Are the resurrected animals the same as they were before extinction? </h1>
Some research projects use the "backcross breeding method".
For example, the White zebra and the extant zebra belong to the same species. So the scientists chose the zebra that looked most like the White zebra to breed. The goal is to get animals that look like White's zebras after several generations of breeding.
Other projects deal with assisted reproduction and genetics. Some use cloning techniques; some use stem cell science...
For example, Professor George Church of Harvard Medical School is dedicated to creating mammoths by "editing" their genes into elephant cells.
But are these animals the same as before they became extinct? The answer is no! After the experiment was completed, Church was unable to create a real mammoth, but instead created an elephant with a small piece of mammoth DNA cleverly placed inside. It will have long, fluffy fur, thick body fat, and hemoglobin, which can deliver oxygen to all parts of the body at sub-zero degrees.
It would be an elephant that looked like a mammoth, but was actually an elephant whose DNA had been altered, so it could live in a cold environment. If you prefer, you can also call it a "mammoth elephant" or "elephant mammoth".
We can use preserved mammoth DNA to create elephants with mammoth characteristics
Beyond that, we now realize that all animals are the product of DNA and the environment in which they live, and the interactions between the two.
Born in the laboratory, transferred to the womb of a modern elephant and bred, and then grown up in a very different environment from the mammoth era, this new era of thick-skinned animals will have different experiences than ice age behemoths. All these factors make it less similar to the original mammoth.
But does it matter? Many people believe that if the resurrected animal looks and behaves like its predecessor, it will be enough.
<h1 class="pgc-h-arrow-right" >03 Can we resurrect dinosaurs? </h1>
Sadly (or thankfully), a realistic version of Jurassic Park is impossible. There are limits to which species can be resurrected. First, scientists need to have a source of animal DNA.
Sometimes, DNA comes from preserved museum specimens, or from cells collected and frozen from living animals. Sometimes, this can come from fossils.
In a scene from the movie Jurassic Park, Laura Dern and Sam Neill rescue a lone triangular dinosaur
But DNA breaks down over time, which means that millions of years later, there won't be any DNA left at all. Dinosaurs went extinct 65 million years ago, so their DNA disappeared forever. Without DNA, there would naturally be no dinosaurs. Therefore, I have to regret to tell you that Hollywood is full of lies.
If you abandon your plan to resurrect the dinosaurs and plan to resurrect a dodo (an extinct bird), I can only say sorry to you again. Although the dodo went extinct relatively late, only a few hundred years ago, its final resting place was Mauritius, a place so hot that DNA could not be preserved at all.
Although the dodo was only extinct in the 16th century, we don't have any DNA samples to clone it
<h1 class="pgc-h-arrow-right" >04 What is the significance of resurrecting extinct species? </h1>
We have enough reasons to resurrect extinct species. Any animal plays an important role in the ecosystem in which they live, so when a vanished species returns, the "job duties" they once performed will also return.
For example, the furry mammoth acts as a gardener. They knock down saplings, eat weeds, and fertilize the land with nutrient-rich manure. When they disappeared, horticulture stopped, biodiversity plummeted, and dense mammoth grasslands were replaced by species-poor tundra.
Studies have shown that if large herbivores return to the northernmost tip of the planet, biodiversity will increase again. The same may apply to other extinct species.
Resurrecting extinct species can help improve biodiversity and help restore fragile ecosystems to health. It can be used as a protective tool by resurrecting genetically unique species, such as the gastric frog or the Tasmanian tiger, we can replace not only small branches, but entire branches of the tree of life.
In addition to this, humans can also reap the benefits. The gastric brood frog somehow transforms its stomach into a temporary uterus. Because it has stopped producing stomach acid, it does not digest the pups. If scientists can figure out how this works, it could potentially be used to treat stomach ulcers or help people recover from gastric surgery.
We live in an era of mass extinction of species. Every day, about 30 to 150 species disappear from the earth. Studies have shown that species are going extinct 1,000 times faster today than in prehistoric times.
Resurrecting extinct species is a key way to reduce the harm of species extinction. For the field of biology and nature conservation, reversing the extinction process is undoubtedly significant and is a great cause that can inspire future generations of scientists and conservationists of wildlife.
But resurrecting a species is not simple: first create an animal in the lab, breed it over the years, and finally cultivate a sustainable population that can survive in the wild.
Ecosystems are dynamic entities that flow and change rapidly. However, if a species becomes extinct in recent years, it is possible to return to its original ecosystem. The Tasmanian tiger, for example, went extinct 80 years ago, and its woodlands have remained largely unchanged – then the extinct species could "go home" to live.
05 What is the ideal option for resurrecting extinct species?
It may seem strange to say, but the ideal choice for resurrecting extinct species could be animals that are still alive.
The only two remaining female northern white rhinos on Earth now live together in the Opageta Nature Reserve in Kenya. But they are all old and sick, too close to each other to reproduce naturally.
The world's last two northern white rhinos
As a result, the northern white rhinoceros is "functionally extinct": the African savannah is home to many species, and the large species that once "pruned" the land can now only live like ghosts.
We can save the northern white rhino by resurrecting extinct species. For a variety of reasons, it is easier to revive species that have gone extinct in recent years than it would be to become extinct long ago, and it would be easier to focus on those that are still alive. Northern white rhinos are currently the focus of the Resurrect extinct species project.
<h1 class="pgc-h-arrow-right" >06 Is it unethical to resurrect extinct species? </h1>
Some argue against the resurrection of extinct species, arguing that doing so would be contrary to the laws of nature. These people are wary of genetic modification techniques and accuse scientists of playing the role of God.
But proponents argue that the technology being developed to revive extinct species could find a corresponding principle in nature. For example, some species of lizards can be cloned and reproduced, while the gene-editing process used to revive mammoths mimics the bacterial immune system.
Just as IVF has become a medical technology accepted by the masses, researchers resurrecting extinct species hope that once science proves its value, concerns will fade away.
Opponents also claim that the technology to resurrect extinct species is stealing money and attention from traditional species conservation efforts.
But no major wildlife charity has yet invested in technology to resurrect extinct species, and a success story of resurrecting extinct species may even help draw attention to the plight of wildlife, rather than counterproductively.
In fact, it's too early to know exactly what will happen to resurrecting extinct species, but proponents argue that if we don't even develop the technology to resurrect extinct species, we'll never be able to make a real assessment of its value.
In Seoul, South Korea, the Soo Yansheng Biotechnology Research Foundation Laboratory regularly produces cloned dogs for the National Police, and even clones pet dogs for around £65,000.
Inside the Soo-ion-sang Laboratory facility in South Korea, clone boxer dogs crowd with each other to compete for attention
But while the cloned dog looks like your loyal friend, it won't be exactly the same. Just as identical twins will have different personalities, physical characteristics, and diseases, Pet Dog II will grow into different dogs.
If we can bring animals back to life, can we bring humans back to life? Theoretically, this is also possible.
Take Elvis Presley, for example. Scientists can extract DNA from his signature hairstyle, sequence his genetic code, edit Elvis Presley's "genetic essence" into a normal human cell, and then use that cell to create a cloned baby.
Realistically, it's a terrible idea.
Elvis Presley
Cloning fertile humans is illegal and unethical, a process that involves many risks. Moreover, perhaps the cloned Elvis will be obsessed with drums and bass, wearing the boots of Dr. Martens (a famous German shoe brand) instead of rock and roll and blue suede shoes.
But this bold idea suggests how far science-based technology to resurrect extinct species can go.
Resurrecting Elvis Presley? Maybe not. But what about mammoths and Tasmanian tigers? Maybe it will happen.
<h1 class="pgc-h-arrow-right" >07 Resurrection of extinct species: something we haven't yet learned</h1>
What is the principle of cloning?
Although we have been cloning animals for many years, we still do not understand its actual principles.
In the process, the DNA within the adult cells is somehow reprogrammed into a younger state, which can promote embryonic development.
It's like a phone factory reset operation, but no one knows exactly how it happens or how to have full control over its process.
If this is understood, scientists are more likely to create healthy animals that can survive.
How to protect animals after resurrection?
To be eligible for legal protection, a creature must be listed as endangered, but for that reason, the resurrected animal must live in the wild.
Previous generations of any newly resurrected species will be locked up for their health checked by researchers, during which their legal status cannot be definitive.
Without protection, these animals could be threatened with poaching or habitat loss.
How will the resurrected animals survive in the wild?
All we can do about releasing animals into the wild is study the ecology in which they were previously located and send them to the most suitable environment.
Then, we need to carefully monitor their dynamics: figuring out why a species went extinct for the first time is crucial, and making sure the same thing doesn't happen again.
After many consecutive release attempts, we learn more about how to maximize the chances of an animal surviving.
We're turning back time — scientists are at the tipping line of reversing species extinction. They are extracting DNA from fossils and museum specimens, using some novel high-tech to resurrect a variety of extinct animals.
It's all for one purpose — the idea isn't to create some lonely individuals to put on zoo exhibitions or biotic freaks, but to create healthy populations of animals that can reproduce naturally and survive sustainably in the wild.
Through their behavior, as well as their positive impact on other species in the ecosystem, resurrected species help to help raise the overall level of biodiversity.
Despite the best efforts of conservationists, species are still going extinct at an alarming rate. Resurrecting extinct species is a novel, unfamiliar, and untested means, but it could become an important tool in the species conservationist's toolbox.
In the coming decades, we will be able to assess its value and decide how to use the technology, or whether it should be used or not.
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