Should extinct species be resurrected?


PCould we really one day see the woolly mammoths that disappeared 3,700 years ago? The question might seem absurd, but progress in genetic engineering techniques now makes it possible to seriously consider reviving species that have disappeared or are close to said extinct species (called “proxies”).

The avowed goals of these attempts are multiple, whether to validate the concept of disextinction or to provide an ecological solution to the problem of the release of permafrost due to climate change.

The contributions of CRISPR-Cas9 technology

This technological advance is notably due to the CRISPR-Cas9 genome editing technology, discovered in 2012 by Emmanuelle Charpentier and Jennifer Doudna. This so-called “molecular scissors” technique makes it possible to modify the DNA at a specific location in the genome, in any cell. It reproduces a defense process that naturally exists in certain bacteria. The technique includes a so-called guide RNA sequence, whose role is to target a specific DNA sequence, associated with an enzyme (here Cas9), whose role is to cut the DNA at said sequence. The cell’s natural repair systems will then automatically “glue” the ends of the two pieces of DNA created by the break.

Depending on the desired result (repair, gene inactivation), a kind of repair “model” is integrated or not into the process. Without a template, the repair system acts at each of the new ends of the DNA strand, generating “abnormalities” in the targeted sequence, which repairs or inactivates the gene. Conversely, in the presence of a synthetic DNA sequence serving as a template and – of course – without anomalies, the repair process integrates it at the level of the cut, literally healing or correcting the strand.

If CRISPR-Cas9 technology has long and especially interested medicine or agriculture, it would therefore now have a new utility: disextinction.

Bring back extinct species or create similar species?

“De-extinction” refers to the process of “resurrection” of extinct species by genetic methods, here the use of CRISPR-Cas9. Unlike other older experiments, disextinction does not require living or frozen cells of the extinct species: all that is needed are organic remains – samples of hair, blood, bone – which contain fragments of DNA. These DNA samples then allow geneticists to sequence the genome of the extinct organism. And that’s the rub.

DNA degrading after the death of the organism, it is not possible to have the complete genomes of candidates for resurrection: part of the genetic sequence is always missing, a “hole” of the order of 5%. Closing this hole requires more, better quality samples…and a lot of time. Enough to make a real de-extinction impossible for the moment!

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Fortunately, there is a parade. If geneticists have enough information about the genome of the target species, CRISPR-Cas9 allows them to modify the DNA of its closest living relative, in order to create an artificial genome that will approximate the genetic code of the extinct species. This genome is then inserted into a fertilized egg, then incubated by a female of the nearest living species. The resulting individual is not genetically identical to its extinct cousin, but the key characteristics that made the latter unique are reintroduced.

So scientists working to extinct the woolly mammoth start with the DNA of an Asian elephant and then use CRISPR to reintroduce the characteristics that made the mammoth unique, including the metabolic elements that allowed it to survive in the subarctic tundra (fat, fur…)

Disextinction and ethics: what rights and behaviors for the recreated species?

This practice raises, on the one hand, the question of the designation of these species (What is an extinct species? Is the recreated extinct species an old “royalty-free” species or a new synthetic species? Is it an animal with the rights that derive from it or not?) and, on the other hand, the question of the psychic future of the animal thus created.

Although the subject is still debated, there is a kind of consensus that tends to say that extinction is the death of all members of a species of plants, animals or other organisms. Once a species is extinct, it leaves the current scope of protection (non-patentability) to pass under the regime of the treatment of remains (protected, but appropriable). The ethical question of the status of beings created from these appropriable remains is still little considered, but it must be resolved before they occur in our ecosystems.

The living is not a toy to be played with

Today there are tracks tending to recognize these new old species as wild animals, therefore protected as such. However, there is no consensus, which can give free rein to all commercial initiatives, as the “for profit” status of the Colossal experiment (aiming to recreate a woolly mammoth) demonstrates.

However, the living is not a toy to be played with. Animals – current or recreated – are not (any longer) objects and we can sincerely wonder if bringing back, in a totally artificial universe, one or more specimens whose behaviors we know nothing about is not on the verge of mistreatment.

Indeed, extinction is not only the loss of physical traits, but also of behaviors: gregariousness, mating rituals, feeding and communication techniques are irrecoverable. How will these species learn to behave like their fellows if they don’t have a role model to learn from? And beyond the species, what will be the consequence on the ecosystem (and its balanced community of species) in which such a creature would be reintroduced?

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Why does humanity, a species in its own right, then wish to de-extinguish? Is it a posture of guilt tending to take into consideration the species that we have eliminated by rendering them “ecological justice” through a recreation?

If we go further, this would also amount to establishing a hierarchy of species where humans – of course at the very top of it – would arrogate to themselves the right to decide which ones would have the right to return, because being our victims. But what about the others? Humanity, although it is indeed responsible for the current extinctions, is neither at the origin nor in cause when one evokes all the mass extinctions which have already taken place. Why, then, does our species suddenly want to revive the past and eventually make amends?

Ethical ruptures

Is it the expression of our deep selfishness? Numerous studies show that there is little room in man for selflessness. The observation of extinctions shows the danger that awaits us. Disextinction would then be the product of a thinking biped not wanting to suffer the same fate as its predecessors and ready for all ethical ruptures to make the immutable cycle of evolution lie. An approach in line with a species which, for its sole benefit, does not hesitate to put transformational innovations into practice without asking the question of the long-term impacts of these deployments, neither on its cohabitants nor on its congeners.

It is thus significant to note that, if ethics often serve as a safeguard for human creativity without restraining it, on this subject it is confined to approaches by discipline (in other words in silos, for example by only addressing the problematic of the ethics of reproduction), but little considered as a whole. The requirement of caution thus does not appear in the narratives and there is no general mapping of what this type of reintroduction would imply (for better or for worse). On the contrary, the projects always invoke a “higher reason”. For the mammoth 2.0, it is the fight against the melting of permafrost that is highlighted.

This last narrative starts from a postulate: humanity is incapable of fighting and will not fight against climate change. It must therefore invent “agents” to do this in its place where the risk is most serious, for example at the level of the release of gases and bacteria linked to the melting of permafrost. The mammoth resulting from CRISPR manipulation is one of these substitutes.

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Its original species has disappeared not because of human overexploitation, but because its habitat has changed drastically due – already – to global warming. This situation caused the Asteraceae which he had made his usual food to disappear from the Arctic steppe, to the benefit of the Poaceae which he tasted less (the mammoth, poet, loved flowers). The disappearance of the nomadic herbivore meant that there were no longer enough wanderings to settle the ground, which accelerated the transformation of the habitat into a hostile universe for the latter.

These wanderings also made it possible to preserve the compactness of the land, a fundamental element for it to continue to imprison the permafrost. Based on this observation, the eminent geophysicist specializing in the Arctic sphere Sergei Zimov undertook to recreate an ecosystem capable of accommodating new large herbivores so that they could compact the soil.

Uncertain benefit

This is justified deextinction, and assured animal welfare, since humans have recreated a mammoth-compatible environment before bringing it back. But is it really a mammoth or rather a cold-resistant elephant? Will this environment really suit him?

We also know that methane emissions by herbivores contribute to climate change. Won’t bringing big issuers back for uncertain benefit be worse than the harm?

What will politicians really do with it?

The use of CRISPR-Cas9 technology as a deextinction tool raises many questions. Admittedly, reintroducing a reconstituted species would be advantageous for conservation by making it possible to restore a certain genetic diversity or ecological interactions. It could also promote the conservation of endangered species: introducing ‘extinct traits’ into species struggling to adapt to a rapidly changing environment could help them survive (and avoid their own extinction).

However, we should not be naive. Faced with these new facilities, removing (or postponing) the very real immediate dangers of extinction, what will the political leaders, whose lack of eagerness to deploy the actions necessary to face the imperatives of climate change, do?

* Caroline Gans Combe, Associate professor Data, econometrics, ethics, OMNES Education


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