De-Extinction

The De-Extinction Ethical Debate

The thylacine, passenger pigeon and great auk, three de-extinction candidates.

The thylacine, passenger pigeon and great auk, three de-extinction candidates.

Examining the Troublesome Ethics Surrounding the Controversial Attempt at Genetically Resurrecting Species From Extinction

Note: This is the abridged version of an essay I wrote that was a semi-finalist in the Professional and Moral Reasoning Essay Contest at the University of Southern California’s Undergraduate Writers’ Conference.

Part 1. De-Extinction

On July 30th, 2003, scientists from Spain and France brought a species of wild goat called the bucardo back from extinction. Ten minutes later, the scientists watched the bucardo become extinct again.

For thousands of years, the bucardo inhabited the soaring cliffs of the Pyrenees that divide Spain from France. But once hunters began to hunt the bucardo, it only took a couple centuries to drive them to extinction in 1999, a barrier once thought irreversible. But using the cells of the last known bucardo survivor, a female named Celia, a team of reproductive scientists injected nuclei from her cells into the eggs of goat surrogate mothers. It took 57 implantations to make seven of the goats pregnant and from those seven only one gave birth to an actual animal. The clone, produced from a hybrid between a Spanish ibex and a goat, was doomed from the start as it had a severely deformed lung. But this was a huge breakthrough in scientific history: had extinction finally been reversed? 

The answer is not quite yet. The bucardo was as close as scientists have gotten to de-extinction, but the clone was not viable. Science has made strides in the 15 years since that bucardo desperately gasped for breath, and many believe that producing a woolly mammoth or passenger pigeon is years away instead of decades. But only certain species can be brought back. The limit for finding useful genetic material is probably in the last million years (unfortunately, no dinosaurs for Jurassic Park fans), and many of the species being talked about as possible de-extinction candidates, such as the great auk, thylacine, and stellar’s sea cow, all died within the last few hundred years. Unfortunately, many of their deaths are directly due to humans altering their habitats or hunting them to extinction.

But is de-extinction a worthwhile investment of valuable funds and resources at a time when our planet is in the midst of a man-made mass extinction? The fact that this science has progressed to the doorstep of what was once thought science fiction is incredible, but de-extinction raises some very uncomfortable questions about nature and our place in it. Where would these animals from bygone eras go in a rapidly changing world? If these animals were produced in the lab would they even be animals? Are we playing god?

In this article I will highlight the difficult ethics behind this potentially incredible scientific breakthrough. Although seeing a thylacine or a woolly mammoth or even a passenger pigeon in real life would be amazing, de-extinction is ultimately a misguided, and possibly destructive, alternative conservation pathway.

Those who could be brought back: Image 1: thylacine at the Melbourne Museum, Image 2: Dodo at the Oxford Museum of Natural History and Image 3: Steller’s sea cow at the Harvard Museum of Natural History.

Part 2. In Favor of De-Extinction

Two centuries ago, the passenger pigeon seemingly would have been the species least likely to go extinct. As recent as 1880, the pigeon was the most populous vertebrate on the North American continent. A single passenger pigeon nesting ground once occupied the space of 37 Manhattans, or 850 square miles. The bird’s massive flocks could blotch out the sun for days while they flew overhead. Their seemingly impenetrable size led people to hunt them for sport and their meat to be sold by the ton. They went extinct in the wild in 1900, a cruel testament to humans’ ability to affect nature. The last of the species, known as Martha, died in the Cincinnati Zoo in 1914.

Stories like that of the passenger pigeon are all too common over the past few centuries as humans have dominated and subjugated nature. Thylacines were exterminated from Tasmania because of the misguided belief that they hunted livestock. The last one died in captivity in 1936. Great auks were first killed by hunters navigating the North Atlantic waters that surrounded their island homes simply for food as they crossed the ocean. Soon their feathers became a commodity, making the birds so rare that they were killed just for museum collections toward the end of their run. The last two great auks were clubbed to death in 1844 for a collector. There are thousands of species that share these creature’s tragic fates of extinction at the hands of humans. De-extinction’s greatest attribute in most eyes is granting us the opportunity to undo the gravest sin we have done to nature: wiping these creatures out.

Many people and scientists think we have a duty to bring these species back, if possible. These include the scientists at Revive and Restore, a bio-genetics lab currently working on de-extinction efforts for mammoths and passenger pigeons. Revive & Restore hopes to create a passenger pigeon by 2020, although they acknowledge that 2025 is the more likely date. First they would have to sequence the passenger pigeon genome and genetically engineer it into a similar living species, such as the banded-rock pigeon. But this is still years, and a couple scientific breakthroughs, away.

But Revive and Restore also offers an interesting additional reason for bringing back the passenger pigeon besides the fact that it is simply “morally” right. They claim that the pigeon played valuable ecological roles that current birds can’t replicate. They knocked dead branches off of trees when their huge flocks would land and excreted tons of fertilizer that benefitted the growth of their deciduous forest home. For species whose ecosystems have not been drastically changed, this argument is an actual justifiable one (but this would be an incredibly rare occurrence for ecosystems to not drastically change).

Other proponents for de-extinction include the wealth of knowledge that could be attained from living animals as opposed to taxidermy, as well as the fact that the process could lead to genetic breakthroughs that could help secure current endangered populations. My personal favorite argument for de-extinction is the wonder factor. There is no arguing that people, including myself, would be blown away to see a living saber-toothed cat or a woolly mammoth. Even seeing the resurrection of an Australian gastric-brooding frog (a frog that births from its mouth) would be incredible to witness in real life. But unfortunately, life and death on our planet is not that simple.

Part 3: De-Extinction is Ethically Wrong

Right now, as negative human impact on the environment rapidly increases, no matter which way you look at it, the negatives of de-extinction outweigh the positive. First off, where are we going to put these animals if we could ever bring them back? The woolly mammoth’s old stomping grounds in Siberia have greatly changed from grassy steppes to moss-dominated tundra since the mammoth died out at the end of the Pleistocene period, also known as the Ice Age. It is one of the areas of the globe most ravaged by climate change. Scientists argue that the return of the mammoth would actually help halt the rapid melting of the permafrost (and the release of heavy amounts of carbon into the atmosphere with it) because they compact the snow when they stomp around, keeping it cool. But to make any negligible difference would require a huge amount of woolly mammoths who are not equipped to live in those areas now. The simple fact is that the ecosystems they left behind have evolved without them. Climate change is making these ecosystems change faster than ever before, especially as it relates to the mammoth’s melting habitat.

The second is the fact that it takes funding away from current conservation of endangered species. At its worst, it even has the potential to severely damage all wildlife conservation efforts by taking the finality out of extinction, the force that drives all of these efforts. If we can bring extinct animals back, what is the urgency to protect them in the first place?

De-extinction is also still unproven, with only a doomed infant bucardo to show for it so far. The science is rapidly evolving and the processes for de-extinction are beginning to be fleshed out, like the work that Revive and Restore is doing to place an intact mammoth nucleus into an Asian elephant egg or sequencing the passenger pigeon genome. But these are still unproven and years away from being tested. Endangered animals are quickly tumbling down into the black hole of extinction as we speak. Urgency is of the utmost importance and valuable resources are being shifted to science vanity projects like resurrecting extinct species. Many scientists would argue that the genetic breakthroughs used to try and clone a mammoth would be much better spent trying to save the Northern white rhino, a species teetering on the edge of extinction with only two female members left. Between taking the bite out of extinction and shifting funds and scientific ingenuity away from actual wildlife conservation efforts, de-extinction can be incredibly damaging.

Finally (and there are many more reasons), de-extinction is a very grey area in terms of ethics. Many argue that de-extinction is playing god, but I do not think that is a good argument. The sailors who clubbed the last two great auks to death on Edley rock in 1844 were playing god when they wiped out a species. But say we produce another great auk, would that really be a great auk, or even an animal?

Great auk specimen, Natural History Museum, London.

Great auk specimen, Natural History Museum, London.

It would need to be carried by a surrogate mother, which raises animal cruelty issues. Think of the 57 goats that were forcefully had bucardo genetic information transplanted into their eggs. The animal would still have genetic information of a different species, which would be bred out over subsequent generations. The subsequent breeding would be problematic for thylacines who were already experiencing low genetic diversity in the population before extinction. Being inbred even more would be disastrous. Even by breeding it with other great auk clones, it would never quite be the same as the great auk that once was. It would have to be made in a lab, questioning its existence as an animal at all.

In an article for the Stanford Environmental Law Journal, environmental lawyer Norman F. Carlin concludes that re-engineered species would technically be products of human ingenuity and not animals, more similar to a vaccine or an invention than to a living creature. A similar parallel is genetically modified organisms (GMO) like GMO crops, whose use has caused widespread debate over the past few decades. If people are weary of GMO corn, a GMO saber-tooth cat may spark some controversy.

Smilodon fatalis at the Natural History Museum of Los Angeles County.

Smilodon fatalis at the Natural History Museum of Los Angeles County.

As amazing as seeing these creatures in real life would be, and as much as it would make us feel better about the past travesties we have brought upon nature, de-extinction is the wrong course of action. These species, from the great woolly mammoth to the ivory-billed woodpecker, should be seen as tragic examples of what we could lose as more species are pushed to the brink. Saving the endangered species of today and charting a new, more environmentally conscious path should be our sole focus instead of trying to right the wrongs of the past by chasing ghosts.

All artwork and pictures by Jack Tamisiea.

Related Article: https://www.naturalcurios.com/natural-curios-blog/2019/3/23/thylacine-australias-premier-de-extinction-candidate

Sources:

Rich, Nathaniel. “The Mammoth Cometh.” The New York Times, The New York Times, 27 Feb. 2014

Sherkow, Jacob S., and Henry T. Greely. “What If Extinction Is Not Forever?” Science, American 

Association for the Advancement of Science, 5 Apr. 2013.

Shultz, David. “Bringing Extinct Species Back from the Dead Could Hurt-Not Help-Conservation 

Efforts.” Science, AAAS, 27 Feb. 2017.

Zimmer, Carl. “Bringing Them Back to Life.” National Geographic, National Geographic, Apr. 

2013.




The Thylacine: Australia's Premier De-Extinction Candidate

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The thylacine, aka the Tasmanian tiger, was brutally and thoroughly wiped out by humans less than a century ago. Today it lives on in the nation’s collective imagination as a possible candidate for resurrection. In this post, I analyze both the physical and moral boundaries to right this ultimate wrong.

Over my time in Australia, I have come to sympathize with the thylacine as I learn more about it and its tragic demise. I have seen thylacines stuffed in museums, a baby thylacine embalmed in alcohol, and have drawn and painted it multiple times, but the incident that sparked the most visceral reaction from me was at the March 20th World Science Festival Brisbane discussion titled Bringing Them Back. This experience, as well as repeatedly seeing thylacines wherever you go in Australia, is why I want to write this piece before writing about the de-extinction debate as a whole.

Being in Australia, the thylacine, or as some locals call it, the ‘Tassie Tiger’, was one of the central focuses of the hour and a half discussion. Before the panel was introduced, the screen played video of the final few thylacines, mulling about in tiny zoo enclosures with audio clips from people who saw them. The presentation was also accompanied by a life-size thylacine puppet (which was a little goofy, for such a grave part of the presentation).

The video clips were what stood out to me because I think this was the first time I had ever really watched an extinct species when it was alive. The thylacine was an incredibly beautiful animal, from its lean frame to its deep, dark eyes to its “tiger” striped back, and it was a depressing sight to see them pacing around their fenced enclosures, a species on the verge of being erased from the world altogether, cooped up in some zoo. The other thing that struck me was how non-threatening and shy they looked, a far cry from the sheep-hunting wolves they were made out to be.

A Brief History of Thylacines

Although the most recent thylacine was confined to only Tasmania, its prehistoric ancestors once roamed across the Australian mainland and up to Papua New Guinea. Thylacines ranged in size from cat-sized to apex predators that weighed almost 130 pounds, larger than today’s wolves. Over ten species of thylacines have been found around Australia, from Victoria in the south to Queensland in the north, and all were predators, with more recent species like Thylacinus potens looking increasingly dog-like and similar to the modern thylacine. The similarities to dogs extended past appearance even down to the teeth, with recent thylacine species having similar molars to modern dogs.

The similarities to dogs is an interesting example of convergent evolution because thylacines are not even remotely related to dogs. Thylacines, similar to almost all Australian mammals, were marsupials, with females having backward facing pouches where they nurtured their premature young. Dogs are placental mammals, the other large group of mammals that has dominated the rest of the globe but (thankfully) did not make it to Australia before it broke off from the supercontinent Gondwana. The similarity in appearance and life style is due to convergent evolution, or two unrelated animals developing similar traits or body types independently of one another to fill similar ecological roles. Another example is the wings of birds and bats being anatomically similar even though they are not related.

The recent Tasmanian thylacine is one of the only large carnivorous marsupial to survive into modern times, with the Tasmanian devil. It was isolated to Tasmania because thylacines all over Australia were outcompeted by actual dogs, when Australia’s iconic wild dog, dingos, were introduced by Asian seafarers a couple thousand years ago. The dingo ate the same food as the thylacine, when it wasn’t eating the thylacines themselves. By that time, however, Tasmania and Australia had separated and the thylacine was hanging onto one last stronghold.

Why are Thylacines Gone?

Thylacines were hunted to extinction by humans. Early settlers of Tasmania believed the animals were a danger to their sheep and other livestock and began a century of intense hunting (between the introduction of the bounty in 1830 to the end of hunting in 1909, over 2,000 thylacines were killed, a mortal wound for the population). Many of the reports of thylacines killing livestock many times their size were probably overblown. Sometimes pictures of them eating livestock were staged with taxidermy thylacines. Whatever their impact on farmer’s sheep actually was (thylacines mostly ate smaller rodents, birds and small marsupials), thylacines were shot and poisoned as pests just the same.

The last thylacine was captured and put in Hobart Zoo, dying three years later in 1936. But reports of the elusive animal still living in the misty forests of Tasmania continues to this day, with an Australian magazine offering over $1 million Australian dollars for the capture of a living thylacine. To the best of my knowledge, one is yet to be captured in the futile chase.

How Could Thylacines Come Back?

At the discussion last week, one of the panelists was Professor Andrew Pask, from the University of Melbourne, who has passionately pursued the de-extinction of the thylacine. He has worked with natural history museums all over the continent that house many preserved thylacine specimens (the thylacine was rapidly collected as it disappeared). One of these specimens was a preserved thylacine pup in Melbourne’s Museum that Pask and his team used to sequence the species’ entire genome in 2017, making it one of the best genetically understood extinct animals.

Knowing all of this genetic information let Pask properly put it in the marsupial family tree (in a sister lineage to the Tasmanian devil) and make some startling discoveries about the genetic health of the thylacine’s population even before it was hunted to extinction. According to what they found in the genome, the population was already in genetic decline due to being isolated on Tasmania. This lower genetic diversity would have made them more susceptible to diseases similar to the outbreak of cancer Tasmanian devils are currently facing. What initially saved them from dingos, geographic isolation, may have eventually been their undoing had humans not intervened to make it more swift.

But with all this genetic information, scientists like Pask are closer to creating new thylacines and perhaps artificially increasing the genetic diversity the species was losing. But this is still a long way away and starts with the need to find a suitable surrogate for possible fertilized thylacine eggs (still years and many breakthroughs away). Unlike woolly mammoths that have a close relative in Asian elephants, thylacines were the last member of their lineage and would need to be carried in another marsupials pouch. But being marsupials could actually prove beneficial. Marsupials spend much less time in the womb than other mammals and it may be easier to stick a marsupial in another marsupial’s pouch.

Preserved thylacine pup at the Australian Museum in Sydney.

Preserved thylacine pup at the Australian Museum in Sydney.


But more information still has to be gathered from thylacine specimens, especially the 13 preserved joey (juveniles from pouch) specimens preserved in museums around the globe. Pask and his colleagues are even beginning to use 3D modeling and CT scanning to study these very valuable and fragile skeletons without destroying the specimens, similar to how scientists study ancient mummies. These models have helped scientists study the thylacine’s growth and development while in the pouch, something that is incredible for an animal that has been extinct for almost a century.

There is still much to learn about thylacines but the amount of specimens, especially juveniles preserved from their mother’s pouches, have given scientists a tremendous amount of genetic and biological information for an extinct species. The next process will be to try to form a fertilized Tasmanian tiger egg.

Should We Bring Thylacines Back?

The de-extinction conversation always ties back into should we bring species from a different time into the modern, rapidly changing world? I’ll dive into the ethics of de-extinction a bit more in a future piece, but I want to focus on specifically the thylacine here.

Andrew Pask, who has devoted his life to resurrecting the thylacine (so he is biased), outlined a few reasons why bringing them back would be beneficial and worthwhile. First, compared to other species like the woolly mammoth, the thylacine has not been gone for very long, dying out a little over 80 years ago. This fact leads to his second big point that because of the relatively short amount of time since they’ve been gone, their environment has not drastically changed since they were eliminated. This means they would have somewhere similar to go back to, unlike the woolly mammoth and the rapidly declining permafrost. And lastly, the thylacine, as top predator of that area, actually served an important ecological niche and reinserting them back on Tasmania would help keep the populations of other marsupials and small mammals in check. Thylacines coming back could possibly create a more balanced ecosystem.

There are a whole lot of arguments about whether thylacines created in a lab would actually be thylacines and would their instincts be gone if they were artificial. The big argument against de-extinction that I believe is that it takes away resources from endangered species facing a similar fate. Think of all the money being spent to sequence the thylacine genome and 3D model specimens when other animals are rapidly going extinct and we are still not sure if de-extinction is even possible.

If the thylacine could come back from the once permanent realm of extinction, it would be incredible and I would be one of the first in line to see a living thylacine. But I believe conservation of current Australian species facing dire situations should outweigh extensive de-extinction efforts. In extinction, the thylacine has become a powerful symbol of what could be lost if we do not change our ways. Bringing it back could take the finality out of extinction and doom hundreds of other species.

Stuffed thylacine at the Melbourne Museum.

Stuffed thylacine at the Melbourne Museum.

Sources:

https://australianmuseum.net.au/learn/australia-over-time/extinct-animals/the-thylacine/

https://australianmuseum.net.au/blog-archive/museullaneous/investigating-a-picture-of-an-thycaline/

https://australianmuseum.net.au/learn/australia-over-time/extinct-animals/thylacinus-potens/

https://australianmuseum.net.au/learn/animals/mammals/dingo/

https://pursuit.unimelb.edu.au/articles/secrets-from-beyond-extinction-the-tasmanian-tiger

https://pursuit.unimelb.edu.au/articles/extinct-tasmanian-tiger-now-back-in-3d