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To de-extinct or not to de-extinct?


On Thursday (31 January) evening, Intelligence Squared U.S. organizes a debate on de-extinction, where proponents and opponents of the notion will present their arguments on this controversial topic.


One of the significant ways humans affect the environment is by causing or accelerating the extinction of other species. This happens at such a rate as to give birth to the terms “Holocene or Anthropocene extinction” and “sixth mass extinction”. Extinct species were until recently considered as forever lost from the biosphere. However, as our knowledge in reading, understanding, and synthesizing DNA advances, the idea of de-extinction has come forward as a plausible application of synthetic biology.

The prospect of bringing extinct animals – most, if not all, de-extinction initiatives focus on recently extinct vertebrates – is a matter of intense debate. The topic has scientific, ethical, and resource management implications, while there are still questions about the technical feasibility of such an endeavor.

The upcoming debate on de-extinction entitled “Don’t Bring Extinct Creatures Back to Life” hosts Ross MacPhee, Lynn Rothschild (for the motion), Steward Brand, and George Church (against the motion). The event webpage also contains a poll for the public to agree or disagree with the motion.

A due correction of errors past

The main argument supporting de-extinction initiatives is the responsibility of humans to alleviate the damage done to ecosystems. In this light, de-extinction is just a correction of a previous human intervention with negative effects.

Extinction of key species can cause ecologic imbalances, especially if done rapidly. De-extinction can become a powerful conservation tool, rescuing ecosystems from collapse and preserving delicate balances. Going a step further, de-extinction and targeted species introduction can be part of targeted geoengineering and climate change-mitigation efforts – as in the case argued for the reintroduction of extinct megafauna in the arctic.

Focus on endangered species instead

The introduction of extinct species into an ecosystem will have complex and unpredictable results, many of them negative. Opponents of de-extinction argue that such risks outweigh the potential benefits and fear unsuccessful environmental management actions.

Another counterargument is based on the methodology that would be used to bring an extinct animal back to life. Provided that there is a full DNA sequence available and a closely-related existing species, scientists could edit the genetic material of an egg and implant the modified embryo to a suitable mother. Even if the (significant) technical challenges are resolved, the animal born would be a contemporary animal with some “extinct” characteristics. The ecosystem, the social structures, and the population diversity of the past do not exist anymore, making the new animal a genetic proxy of its extinct counterpart.

Mexican Wolf. Approximately 143 individuals are living wild. Image by Jim Clark, U.S. Fish and Wildlife Service (Public Domain).

The main argument against de-extinction comes from a conservation biology point of view. Focusing on de-extinction could compromise biodiversity by diverting resources from preserving ecosystems and preventing newer extinctions. It could also reduce the moral weight of extinction and support for endangered species, giving the false impression that reviving an extinct animal or plant is trivial.

A philosophical debate

The majority of articles, videos, or conversation contain at least one cultural reference that provokes strong associations – Pandora’s Box, Prometheus, Jurassic Park. The debate touches upon our relationship with nature, finiteness, and how life and death are perceived. It is therefore quite difficult to make an objective generic assessment and get a definite answer on whether de-extinction is a good or a bad thing. The sentimental factor plays an important role, whether the take is on reviving the passenger pigeon or not repeating past mistakes.

I personally see no ecological, conservational, or any other benefit in reviving a wholly mammoth. But I think that the technology is intriguing and could pave the way for interesting applications or even new scientific fields. The process can teach us more about environmental dynamics, animal genetics, developmental biology, and genetic engineering. Nevertheless, the skepticism is healthy and helps keeping applications in check and overhyping low. And I would like to believe that releasing an extinct animal into the wild, if it ever happens, will be a well-thought process with a broad societal consensus.

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