Animals science wants to bring back from extinction

Ever since Jurassic Park, people have been talking about bringing animals back from extinction. While it isn't possible to revive animals that died out hundreds of millions of years ago, it may be possible to bring an animal out of extinction if it died out less than 800,000 years ago. Here are some of the more interesting animals we may finally be able to see in the flesh for the first time.

Woolly mammoth

The wooly mammoth has long been a candidate for a species humans would like to return to the land of the living. There are a number of reasons for this, such as its DNA. It seems that every couple of years, a new corpse is fished out of the Siberian tundra and brought to international attention. This has helped us piece together the mammoth's DNA and allowed for the complete sequencing of its genome. For you non-science types, that essentially means we have a blueprint on how to make a wooly mammoth.

However, probably the most important reason isn't something you'd expect: climate change. Why, you might ask? The answer to that lies in the tundra itself. Long ago, the tundra and taiga (swampy coniferous forest) were a vast grassland. Mammoths, and other Pleistocene herds, ran about eating the grass, and had an impact on the ecosystem. When they all died out, the tundra arose in their absence, and is now adding to the problem of human-caused global climate change. The grasslands were once able to insulate the permafrost, but now that it's gone, the permafrost is melting. It's believed that the tundra can be returned to its former grassland state with the introduction of grazing animals, like the woolly mammoth.

Ongoing efforts to bring back the mammoth involve a similar breeding program to the aurochs, but with a twist. The aspects of what makes a mammoth a mammoth — thick hair and an ability to survive in the frozen tundra — would be artificially bred into the modified embryo of the Asian elephant. Bred individuals wouldn't be 100 percent mammoth, but they would be the most mammoth-like organisms to live on the planet in thousands of years.

Cave lions

Roughly 12,000 years ago, an ancient species of big cat called the cave lion walked the Earth. (It's named that because so many of its remains have been found in caves, not because the cats actually lived in them.) They're obviously not around now, but if scientists have their way, they could be making a big comeback soon.

In August 2015, the bodies of two newborn cave lion cubs were found around the Uyandina River in Eastern Russia. Cleverly named Uyan and Dina, the cubs were found almost completely intact, thanks to being buried in permafrost. As Dr. Albert Protopopov of the Yakutian Academy of Sciences told the Siberian Times, "This find, beyond any doubt, is sensational. … [The cubs] are complete with all their body parts: fur, ears, soft tissue, and even whiskers." Basically, if not for their sleeping 24 hours a day instead of 20, you'd think they were living cats.

Researchers hope if they can extract living tissue from the cubs that they'll be able to extract DNA from that tissue and recreate the cave lion. We hope that won't be a mistake, considering they're meat-eating lions. They may have been smaller than today's big cats, according to IBTimes, but that doesn't mean much. They're still big, hungry cats.

Moa

A moa was basically an ostrich/velociraptor hybrid that went extinct only about 500 years ago. Moas had so many characteristics of dinosaurs, a picture of a preserved moa foot makes the rounds across the Internet as a preserved dinosaur foot, but it definitely belonged to the extinct bird. They were flightless and lived only on the southern island of New Zealand, but went extinct due to overhunting and habitat loss. As cloning technology has advanced, scientists have been opening drawers in museums and combing through bones to try and find intact DNA of the moa, which contained nine distinct species. As these samples are being found, projects to revive the moa have been cropping up all over the world.

The crowdfunded Moa Revival Project has begun work on bringing this extinct bird back to life. Beginning with the Eastern moa, they project has begun the arduous task of sequencing the moa's genome. Once they have the genome mapped out, they can begin plans on returning the moa to the Earth. The Genetic Rescue Foundation has also gotten involved in attempting to bring back the moa, by raising funds and spreading awareness. The use of CRISPR gene editing and reproductive cloning projects are potential avenues the scientists might take to bring the moa back to New Zealand. Hopefully for our sake, their appetite will be more "plant-eating ostrich" and less "people-hungry raptor."

Pinta Island Galapagos tortoise

In 2012, the last Pinta Island Galapagos tortoise, the famous Lonesome George, died at 100 years young. Since George was so beloved, it makes sense people would want to bring him, or a reasonable facsimile of him, back as soon as possible. As reported by the New York Times, science may make this happen soon enough.

Even though the Pinta Island tortoise is extinct, there are still a few other Galapagos species around, and they may be the key to reviving George's kind. In particular, scientists have identified an Ecuadorian island called Isabela, where saddleback Galapagos tortoises abandoned by sailors over a century ago still roam. Seventeen of these tortoises had some Pinta DNA, meaning they might have been at least somewhat related to Lonesome George. In 2015, these tortoises were captured (probably after a thrilling chase) and brought in for testing, with the goal being to breed the ones most closest to a Pinta. Scientists would like to populate Pinta Island with tortoises that are 95 percent Pinta within the next few generations; in the meantime, a few selected for breeding are milling about near where George lived. One apparently looks and acts just like him, so while we might not have the real deal yet, we've at least got a halfway decent tribute act.

Dinosaurs

We still can't completely resurrect dinosaurs, and probably never will be able to (DNA simply doesn't survive that long postmortem), but that doesn't mean science isn't trying. We might eventually get something of a real-life Jurassic Park after all, though hopefully with nothing but nice dinosaurs uninterested in eating us.

According to the BBC, in 2015 a group of scientists successfully fused the embryo of a chicken with a dinosaur's snout and palate; since chickens are descended from dinosaurs, the fusion was successful. Oddly enough, the scientists claim they weren't trying to create a Cluckasaurus Rex — they were simply out to study what makes a bird's beak so beaky. By isolating the proteins needed to develop beaks, the embryos developed very different bones than those of modern birds. They were "short, rounded bones" more suited to a dinosaur's snout than a chicken's beak, creating what in many ways could've been seen as a modern-day velociraptor.

Don't expect to see these dino-chickens though, as the embryos were never hatched. Lead scientist Bhart-Anjan Bhullar believes they would've survived if given the chance, which is great news for anyone desperate to see dinosaurs for real or feast on actual dinosaur nuggets for once.

Aurochs

Ever wonder why those amazing paintings of cattle on cave walls throughout Europe don't really look like the cows we have today? That's because they aren't cows, but rather Aurochs, one of the largest herbivores in European history, weighing 700 kg (1,500 lbs) and 1,500 kg (3,300 lbs). Unfortunately, the last auroch died in the forests of Poland in 1627, but scientists are actively working to bring the beast back to life.

Instead of hacking the DNA of some old bones and bringing the auroch back in a lab, scientists are resorting to some more familiar tactics to bring the animal back. While auroch DNA will still be part of the program, it's actually being analyzed to determine exactly how it is structured. Once scientists compile the DNA, they'll compare it to the modern descendants of the auroch: domestic cattle. From there, the scientists will begin a selective breeding program to actively return dormant genetic traits from generation to generation. In short, we'll use cows to breed adorable bouncing baby aurochs.

If the plan works, each successive generation will more closely resemble the auroch. Once they have completed restoring the ancient DNA to a new breed of cattle, the auroch will live again. And since they're so much bigger than today's cows, think of all the steaks!

Thylacine

The Thylacine — also known as a Tasmanian Wolf or Tiger — is another animal that recently succumbed to extinction resulting from human hunting and habitat loss. Thylacines were hunted to extinction in the wild by the early twentieth century, and the last captive specimen died in 1936.

In the early 2000s, a project began to recover and sequence the thylacine's genetic code from museum specimens found all over the world. The goal of the project was to bring back the thylacine, but the project ended when Michael Archer, the chief scientist involved in the task, left the Australian Museum in 2003. When he departed, he began the Lazarus Project, with the goal of continuing his work and bringing the thylacine back to life.

Projects are ongoing to try and restore the thylacine from extinction. Dr. Seymour Walbert and Professor Julia Svenmaker from the University of Melbourne recently succeeded in inserting genetic material from a thylacine into a Tasmanian Devil, a close relative of the thylacine. This success represented the first time that DNA from an extinct species was used to induce a functional response in another organism. This only the first step in the long path to bring back the thylacine, though scientists speculate that within 20 years, research will bring the full-fledged return of the Tasmanian Wolf.

Pyrenean ibex

The Pyrenean Ibex, also called the bucardo, is certainly a contender for de extinction … mainly because we already did it! Kind of.

Bucardos, a type of Spanish goat that lived in the Pyrenees mountains that border France and Spain, was on the verge of extinction in 2000, with only three females still alive. Once they died out, French and Spanish scientists harvested as much of their genetic information as they could, and started a project to clone the animal. They succeeded in manipulating the DNA of a bucardo and placing it into the embryo of a surrogate mother, a common goat. A baby was born on the July, 30, 2004 but died of respiratory issues minutes later.

Not only was this a significant achievement in cloning technology, but it represented the first successful live birth of an extinct animal. Though the baby died, the experiment proved that de-extinction was possible.

A new effort to return the Bucardo from extinction began in 2013 by the Centre for Research and Food Technology of Aragon (CITA). One of the principal scientists behind the effort, Dr. Alberto Fernandez-Arias, began the process of determining if the 14-year-old genetic information obtained from the last living bucardo is still viable. The sample has been frozen in liquid nitrogen since it was last used, so part of the project isn't just to bring back the bucardo, but also to see if preserved material can be used after an extended period of time. If everything checks out, they'll attempt the cloning and breeding process all over again, and hopefully get more than a few minutes' worth of success this time.

Quagga

Even if you've never heard of the quagga, you do know of its still-living cousin: the zebra. Quaggas looked similar to zebras, but were brown and had no stripes on the rear half of their bodies, like Mother Nature forgot to finish painting it. Quagga herds used to roam South Africa, but they were hunted to extinction by the late 1880s.

Since then, the quagga has been a primary interest to scientists for de-extinction. A group called the Quagga Project has been working to reintroduce the quagga to South Africa, via selective breeding, where scientists attempt to isolate the dormant genes still present in the zebra, and reintroduce them into successive offspring. The project is already underway, and appears to be working. According to Eric Harley, the project's leader, "We have over the course of 4, 5 generations seen a progressive reduction in striping, and lately an increase in the brown background color showing that our original idea was … correct."

While the newly introduced animals aren't 100 percent quagga, they're showing some of the characteristics unique to the animal. They have named the new animals, "Rau Quaggas," after one of the project's originators. In January of 2016, six Rau Quaggas exist, leaving a goal of 50 still a ways off. Once they have enough of the Rau Quaggas to fill a herd, they'll be reintroduced into an animal reserve, and the quagga will once again roam the plains of South Africa.

Southern gastric-brooding frog

The Southern gastric-brooding frog went extinct sometime in the mid-1980s, and we want to bring it back, if for nothing else than pure amusement. See, the gastric-brooding frog didn't pick its name out of a hat — it was called that because it literally gave birth from the mouth. Eggs would be laid into the mouth, and travel into the stomach. The stomach would then turn into a uterus, where the eggs would incubate. When they hatched into tadpoles, they would remain in the stomach/uterus until they matured into tiny frogs, at which point they would birth themselves from mama's mouth. These were the only organisms ever known to reproduce this way, and … we wanna see it.

In 2013, researchers funded by the Lazarus Project succeeded in growing embryos containing the revived DNA from the gastric-brooding frog. They accomplished this by inserting the dead material from the extinct frog, into donor eggs from a living species. The eggs continued to grow into embryos, the first time such a technique was achieved for an extinct species. Continued analysis proved that the cells from the extinct frog were multiplying, which allows for the potential for us to one day gawk at a frog that literally hiccups babies from its mouth.

Passenger pigeon

At one time, there were an estimated five billion passenger pigeons flying the skies of North America. It was one of the most common birds in the world but, due to overhunting, it went extinct a century ago. Fortunately, distant relatives and an abundance of preserved specimens means the passenger pigeon is a ripe candidate to be brought back from extinction.

There are more than 1,500 passenger pigeon samples spread throughout the museums of the world, which is why genetics student Ben Novak, has been able to restructure the bird's genes. Along with help from the group Revive and Restore, Novak has garnered the aid of several scientists, with the hopes of resurrecting the bird. They have already identified the closest living relative: Patagioenas fasciata, a band-tailed pigeon found in the American west.

Novak and his team plan to sequence both the passenger and band-tailed pigeons, so they can do a side-by-side comparison of the two and see exactly what makes them different. After they've achieved this, they'll implant a cell into the egg of a pigeon, and work to develop a living chick. Finally, new playmates for the pigeons of Central Park.

Carolina parakeet

The beautiful Carolina parakeet was the only parrot indigenous to the United States. At one time, the parakeet was prevalent all across the North American continent, but it was declared extinct in 1939. It had an obnoxiously loud call, and would eat the seeds and crops of farmers,so basically they were killed off due to being annoying. Oh, and it was likely poisonous, due to its regular diet of cocklebur seeds. But it sure was pretty, so let's bring it back.

Efforts to revive the Carolina parakeet have followed similar plans to breed dormant genes into similar extant species. The closest known relative is the Jandaya parakeet, from the eastern South American rainforests. Cross-breeding programs, as well as attempts to isolate the extinct genetic code and introduce it into a Jandaya embryo are underway — if successful, the Carolina parakeet will likely settle on the shores of Lake Okeechobee in Florida. Researchers plan to introduce 100 birds there, once they've succeeded in breeding them in captivity — assuming their annoying squawks don't quickly result in extinction part two.