Last week, researchers from the University of Melbourne announcement this thylacines or Tasmanian tigers, Australia’s predatory marsupials that have been extinct since the 1930s, may one day come back to life.
The announcement led to some overhyped titles on the imminent resurrection of the species. But the idea ofdisextinction» faces a variety of technical, ethical and ecological challenges. Critics (like me) argue that it diverts attention and resources from the urgent and achievable task of preventing the extinction of species that are still alive.
The revival of bucardo
The idea of de-extinction goes back at least to the creation of the San Diego frozen zoo in the early 1970s. This project aimed to freeze blood, DNA, tissues, cells, eggs and sperm of alien and endangered species in hopes of one day recreating them.
The concept caught the attention of the general public with the first of the jurassic park films in 1993. The famous cloning of Dolly the sheep reported in 1996 gave the impression that the necessary know-how was not too far away.
The next technological leap took place in 2008, with the cloning a dead mouse which had been frozen at -20℃ for 16 years. If frozen individuals could be cloned, the resuscitation of an entire species seemed possible.
After this realization, de-extinction began to emerge as a potential way to tackle the global extinction crisis.
Another notable breakthrough came in 2009, when a subspecies of Pyrenean ibex known as cockle (Capra pyrenaica pyrenaica) that had been missing since 2000 was cloned using frozen tissue.
The newborn bucardo died just minutes after birth. But we could no longer pretend that disextinction was limited to the imagination.
Do not neglect anything
There are still technical reasons to think of a real de-extinction may never be possible for many species. But even if these are overcome, the debate over the pros and cons will continue.
Supporters support that with today’s accelerating loss of cash, we must exploit all options. On its own, de-extinction seems like a sensible tool to add to our de-extinction kit.
But it is far from being so simple. Opponents have a long list of reasons why de-extinction won’t help save biodiversity.
An expensive project
One of the main arguments against de-extinction is the huge expenditure required for research and technology. The 5 million Australian dollars paid to the University of Melbourne is just a drop in the ocean.
Ecologists and conservation biologists argue that the money would be better spent on initiatives to prevent extinction in the first place. These include buy land to conserve entire ecosystemsdeletion invasive species, restoration of degraded habitatsand programs for raise and reintroduce threatened species.
However, modeling suggests devoting limited resources to deextinction could lead to a net loss of biodiversity.
Prevention is better than cure
Another common argument is that Prevention is better than cure; we should put all our efforts into avoiding extinction in the first place.
If we believe we can somehow “fix the extinction later,” we risk becoming ambivalent. Conservation planning after the fact could be a dangerous path to apathy and higher net extinction rates.
Some have argued that the simple concept of disextinction tests the limits of our ethical notions.
“Playing God” with the existence of entire species is inherently controversial. Research and implementation depend value judgmentswith those in power realizing their values above those of others.
Will the voices of Indigenous peoples be heard when deciding which species to resurrect? Will the dispossessed and the poor also have a say?
There are also serious questions of animal wellbeing both along the path to extinction, as well as what happens to organisms once created (including in captivity and after reintroduction into the wild).
A matter of numbers
Perhaps the most important practical argument against deextinction, but also the most overlooked, is that creating one or two animals won’t be enough to bring back a species.
To have a real chance of surviving in the wild, introduced populations must number in the hundreds or even thousands. Could we create enough individuals to do this?
But even so, we know most endangered species reintroductions fail due to insufficient numbers.
Let’s say we ignore technological challenges, costs, ethics, lack of genetic diversity, etc. Suppose we can make new thylacines, mammoths, diprotodonsWhere saber tooth cats. Awesome. Now where are we going to put them?
Available living space is scarce, especially for large species that need lots of undisturbed territory to survive.
Not to mention human-wildlife conflicts.
What happens if a major predator (like the thylacine) is repelled? Will the pastors welcome them with open arms, or shoot them to extinction like they did last time?
The world has changed
If we were to bring extinct species back to the places where they used to live, there is no guarantee that they would survive there under modern conditions. Climate change and other processes mean that many past environmental states no longer exist.
Just because a mammoth lived in Siberia 20,000 years ago doesn’t necessarily mean it could do so today.
Diseases and invasions
Debates are already underway about moving endangered species to new habitats to increase their chances of survival. Opponents of thisassisted migrationemphasize the risk of spreading disease or pests, or that the relocated species will harm other species in their new home.
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Now imagine you want to introduce a long-extinct species to an area. Would it spread disease or bring down other species?
On the other hand, most species depend on highly specialized microbiomes for their survival. Recently resurrected species could be miss these organisms or succumb to those who live in the area where they are released.
The debate goes no further
As technology advances, we are likely to see many leaps towards the holy grail of resurrecting extinct species. Chances are it’s a recently extinct species rather than something like a diprotodon, or dare I say, dinosaur.
But even so, deextinction is unlikely to offer any real value to global biodiversity conservation.
So should we continue to seek disextinction? The debate is not going away anytime soon. As long as there are punters willing to fund technological research, the chase will continue.
But even the most amazing technological advancements are unlikely to help the catastrophic global loss of biodiversity.