Should we bring extinct species back from the dead? | Environment | All subjects from climate change to conservation | DW

World



[ad_1]

This week, scientists announced a breakthrough in the battle to bring the northern white rhino back from extinction.

The last male of the species died earlier this year, reducing the entire population to only two females. their calving years. But today, advanced reproductive technology and stem cells have produced embryos from frozen northern white spermatozoa and closely related southern white rhino eggs

"These are the first embryos of rhinoceros produced in vitro. "Thomas Hildebrandt, one of the scientists behind the project, said in a press release

that the news offers a fearsome hope that advances in science can repair the wrongs done to creatures by humans a second chance

But just because we can do something, does that mean that we should ?

Pleistocene Park

Scientists have already created embryos with genetic material from the recently extinct gastric-incubating frog, and in 2003, a clone of the last bouq Pyrenean spinel was born for a goat – although it only survived a few minutes.

But they also stage their creatures that have not been on the land for hundreds or even thousands of years.

The researchers managed to decode the entire genome of the Tasmanian tiger, which was last seen alive. 1936, and hopes to be able to edit his genes in the eggs of a surviving marsupial such as his little cousin, the numbat.

Tasmanian Tiger (US National Zoological Park in Washington DC)

Thylacine was the top of Tasmania predator, until aggressive hunting killed all species

And a Harvard University team is working to bring the woolly mammoth back to life in a "Pleistocene park" in Siberia.

Restore & Revive, an organization that promotes "de-extinction", promotes gene editing rather than cloning. Genes that differentiate an extinct species from a surviving species are identified and transferred into the genome of the living animal.

Ben Novak, principal investigator at Restore & Revive, is working on inserting genes from the extinct traveler pigeon into the DNA of a band-tailed pigeon.

"Hidden in the genome of the traveling pigeon are the key mutations to be able to take a bird today and the engineer to be what is a traveling pigeon," he said. said to DW. "It's the idea – it's not about copying, it's about re-creating, re-imagining."

Elephants with funny hair

In the case of the mammoth, genes for the hair shaggy, small ears, subcutaneous fat and "blood antifreeze" that allowed him to grow in temperatures below zero would be published in the genome of an Asian elephant, its closest surviving parent

. a mammoth as such, but a kind of chimera that may or may not have much chance of surviving in the modern world. Or, as said Britt Wray, author of Rise of the Necrofauna: The Science, Ethics and Risks of Detoxification "An elephant with a fun haircut that can live in the north . 19659019] Mammoth skeleton (image-alliance / dpa / Summers Place Auctions) “/>

Putting meat on these bones: Bringing the mammoth back to life is an exciting idea, but is it good?

Wray praised the northern white embryo news as "fantastic," saying that alongside more traditional approaches to conservation, the new technology could "return the script" for some species. But she is less enthusiastic about bringing back creatures from a world that does not exist anymore.

There are many technical challenges to overcome. Even with the complete genetic material of the recently disappeared ibex, the ephemeral infant was the only full-term pregnancy of 57 embryos implanted into surrogate mothers.

Wray points out that the precursor of the cloned ibex, Dolly the sheep, was the sole survivor of 277 clone attempts – and this was in the substitutes of the same species. And even if the animal does, will it behave like its extinct ancestors, without living family to teach it?

"It's a lot of effort to tinker with a facsimile or a proxy of a majestic creature we're in" Wray tells DW

Scientists of the Resurrection say that extinct beasts would not be brought back just for us to admire.Although they are not true members of the extinct species, they could have the physical and behavioral characteristics to fulfill the ecological role of the animal. original.

Restoring Ancient Ecosystems

When a species disappears, the whole ecosystem is

The Aurochs – the primitive cow of Eurasia – supported predator populations , for example, and their created pasture has helped other species such as plants and birds to thrive on the ground.Heck cattle – selectively "reproduced" from domesticated cattle for their wild ancestor characteristics – have included in redevelopment projects aimed at restoring past biodiversity.

Heck Cattle, Oostvaardersplbaden Nature Reserve in the Netherlands (CC BY-SA 3.0)

Heck cattle were bred to mimic their ancestor, with the hope that it would not be possible. they could help restore ecosystems

Even mammoths, argue the scientists of the resurrection, could help turn the Siberian tundra into a grbadland ecosystem as rich in biodiversity as the African Savannah

And this is not the case. is not everything. They even claim that by grazing vegetation and trampling on winter snows, mammoths would expose the soil to colder temperatures and prevent melting of permafrost, which would slow down a dangerous feedback loop on the change. climate change

. Wray warns against pride when it comes to recreating them based on our limited knowledge.

"Ecosystems are not just more complex than we currently think, they are more complex than we think ." This is not a plug-and-play scenario where you delete a variable, then you add it and you return to what it once was. "

Detractors of the Science of the Resurrection Argument of" Moral Risk ": Trying to bring back lost species is a denial of the catastrophic end of extinction, which could lead us to think that we can go back in time even if a species disappears.

Let's not leave it so late next time [19659002] This is a concern for Cathy Dean, director of the British charity Save the Rhino.

She says while wishing all the best to the team that is trying to coax frozen rhinos, its organization will focus on species that They still have the hope of surviving without such complex, expensive and uncertain conservation efforts. 19659039] Sumatra-Nashörner (photo-alliance / dpa) “/>

Deforestation has reduced the Sumatran rhinoceros to a population of less than 80 animals

"Unfortunately, the history of the northern white rhinos has been poor. was completed ten years ago, six animals left Granby National Park, "Dean told DW," You need 20 independent founding animals to have enough genetic diversity. "

Today Now, says Dean, there are less than 80 Sumatran rhinoceroses and 67 Javanese rhinos – a situation although desperate, at least one where there is still enough But unlike Sudan, the last northern white male who died in May, we do not know the names of Sumatran rhinos or Java and they do not make the headlines of international media with online dating profiles or advanced genetic technology.

"I think that it's really a e lesson for all of us that you should not allow a situation to be so desperate, "Dean said. "And the broken heart with the whites of the north is that there were opportunities, there were two very good chances in the mid-90s and again in 2005, which for political reasons were not exploited. "

  • USA Jurbadic Park Movie (picture-alliance / UNITED ARCHIV / IFTN)

    Beasts That Could Return To Extinction

    No Fear Of A Suite Of T-Rex

    films, Jurbadic Park still captivates us with the idea of ​​humans coming up against the most terrifying old inhabitants of our planet. But the fantasy of resurrecting a dinosaur from DNA in the belly of a mosquito trapped by amber is far from reality. Beth Shapiro, a prominent scientist of disembodiment, says that it will not be possible to use genetic material older than a million years

  • Kenya females white rhinoceros North (DW / Andrew Wasike)

    Beasts that could return from extinction [19659047] And then there were two

    Since the last northern white rhino – a 45-year-old Sudanese – has died Earlier in 2018, older women Najon and Fatu are the last of their kind. But scientists hope that freezing embryos could roll back "functionally extinct" species. They were created in vitro from the sperm of a dead northern white male and eggs of closely related southern white.

  • Dodos (Imago / StockTrek Images / D. Eskridge)

    Beasts that could return from extinction

    Not so dead after all?

    When the dodo – a fatally confident and tasty bird – disappeared from Mauritius in the 17th century, few believed that humanity could extinguish the life of an entire species. It was only in the 19th century that the naturalist Georges Cuvier proved that extinction was possible and that the dodo became the symbol of this destructive power. Now, the hunt is launched for dodo DNA, in the hope that we can also prove our power to resurrect.

  • Pyrenees ibex (picture-alliance / blickwinkel / C. Wermter)

    Animals that could return from extinction

    The fragile life

    At the time of the death of the last Pyrenean ibex Celia in 2000, the scientists had already gathered and frozen his oocytes. Three years later, a goat gave birth to the clone of Celia, created by injecting his DNA into the egg of a goat. In fact, dozens of such hybrid eggs have been implanted. Only seven animals became pregnant, and one carried to term – and the resurrected ibex survived only a few minutes after birth.

  • Martha, the last traveling pigeon (Donald E. Hurlbert, Smithsonian Institution)

    Beasts that could come back from extinction

    Pbadage from the past

    This is Martha, the last traveling pigeon, died in 1914. The plump birds of North America were the favorites of the plate, and hunting combined with deforestation even wiped them out as environmental advocates warned of their senseless disappearance. Revive & Restore, an organization that promotes "de-extinction", sees the racing pigeon as the perfect model to show the potential of the science of resurrection.

  • Tasmanian Tiger (Thylacine) [Getty Images / AFP / T. Blackwood]

    Beasts that could return from extinction

    Mother Numbat

    European settlers in Australia put a premium on the head of thylacine, or tiger Tasmania, a marsupial apex predator. The last known member of the species died at Hobart Zoo in 1936. Now scientists have decoded the entire genome of the animal from a preservative in ethanol, and hope to insert its genes into the DNA of its closest surviving parent, a marsupial numbat.

  • Woolly mammoth (Imago / Scientific photo library / L. Calvetti)

    Beasts that could come back from extinction

    Pleistocene Park

    The most impressive species having a chance to come back is the woolly. mammoth, whose closest living relative is the elephant of Asia. Scientists at Harvard University argue that ice age giants could play a role in slowing melting permafrost and, as a result, climate change. But their concept of "Pleistocene Park" would need 80,000 animals to have a real impact – pure science fiction, critics say.

  • Heck cows (Imago / Photo library / P. Clement)

    The beasts that could come back from extinction

    A devil of a cow

    The auroch once roamed the entire length of Eurasia, but hunting and habitat loss erased them almost 400 years ago. Yet, their descendants – domestic cattle – still live, and back-breeding programs have tried to resurrect the auroch by selecting the characteristics of the wild ancestor. A first German attempt resulted in Heck cattle, which were reintroduced in parts of Europe.

  • Nachbildung Neanderthal Eels (picture-alliance / dpa)

    Beasts that could return from extinction

    Meet the Ancestors

    We shared the planet with other human species, such as Neanderthal, with whom we even met. Many of us still carry Neanderthal DNA. But we are also the main suspects in their extermination. How would it be to confront the relationships that we had previously eliminated? Scientists are cultivating the homo sapiens-Neanderthal hybrid brain material in the laboratory to examine the differences between them and us.

    Author: Ruby Russell


[ad_2]
Source link

Tags

Powered by https://naaju.com/ireland | Designed by Naaju
© Copyright 2024, All Rights Reserved