Protecting the critically endangered species still with us

Every few years there is a frenzy in the media about efforts to use modern genomic technology to recreate long-extinct or recently extinct species. Often referred to as de-extinction, it first became heavily discussed after a series of TED talks were posted in 2013; see links below. Extinct species getting all the attention are, unsurprisingly, charismatic species lost either to relatively recent human activities or less-clear causes in the Pleistocene. Imagine a world where we once again have passenger pigeons by the billions darkening the skies of the eastern U.S., where the thylacine is again an apex predator in Australia, where the enigmatic gastric-brooding frog once again is available to inform human medicine with its bizarre stomach-as-a-womb natural history! Imagine seeing live woolly mammoths! This is all very romantic stuff, of course, and so it gets lots of positive attention every time it re-appears in the headlines.

Recently, a major breakthrough in funding (not technology or progress, mind you) was announced in the private venture to use gene editing to bring back “thousands of wooly mammoths to Siberia.” The details for each of the species proposed for de-extinction are a bit different of course, but the general idea is that we conceivably can take DNA recovered from museum specimens or frozen carcasses from the Arctic permafrost and insert it into the egg of a closely related non-extinct species. The embryo or egg then is produced by the proxy species being used as a parent. It is unclear how parenting or social groupings would be managed. Then, through multiple rounds of refinement and genetic editing and a series of such births or hatchings, we will have a very close approximation of the extinct species. In the case of the woolly mammoth, fragments of DNA recovered from the permafrost would be edited into the genome of a modern elephant (they did not make clear which species) and a baby mostly woolly mammoth would be born. Make thousands of these and the new populations will re-engineer Siberia away from the forested peat-lands that it is now and back to the grasslands that evidently dominated the region in the Pleistocene. It’s not clear why this would only take place in Siberia, when we know that the species also was wide-ranging in North America and Europe.

These are interesting premises, no doubt, and the advocates for them are masters at whipping up emotions to assuage our self-aimed guilt for having allowed so many species to go extinct owing to our own influences. In the case of the mammoth, the real cause for their extinction (along with the rest of the vanished Pleistocene megafauna) remains controversial. The evidence for over-hunting by early humans often is presented, but the evidence for climate change during those times also is very compelling. It’s likely that both influences were at play. Regardless of human influences, including current trends in climate change aside, no one can actually be sure that the former range of woolly mammoths is any longer ecologically appropriate for them.

The arguments against these endeavors also are very strong. To be straight with you, I’ll confess that I am strongly opposed to these projects for a long list of reasons. I teach a section in my Conservation Biology course at Georgia Tech on this topic and, every single year, the students all wind up unanimously opposed to these ideas after they have had a week to study all the angles. The romanticism of the concept seems to fall away in light not only of technological challenges (e.g., can we actually do this?), but also of considerable ecological realities. If you read any accounts of the biology of passenger pigeons, as you try to come to grips with the rather unimaginable densities the species attained, it becomes very difficult to imagine that they could exist in the current landscape. It also becomes clear that contemporary people are unlikely to tolerate the intrusion, mess, and crop damage that those numbers of birds produce. It was no accident that our ancestors purposefully eliminated them. Similarly, it was no accident that humans eradicated the thylacine and came frighteningly close to doing so with wolves.

Critics also argue, quite convincingly, that it is hard to justify the expense and effort to recreate a lost species when we are utterly failing so many existing critically endangered species. The recent article touts $15 million toward the effort to de-extinct (pardon my lousy verb!) the woolly mammoth. The final number, including considerable work already accomplished, will be much higher. The African elephant was recently upgraded to Endangered on the IUCN Red List, and the African forest elephant was upgraded to Critically Endangered. Their situation is getting worse at this very moment, which means our conservation efforts for them remain insufficient. Critics argue that ca. $20 million toward protecting what we still have is preferable to gambling on something so uncertain as de-extincting the woolly mammoth. In other cases of much more recent extinctions, like the gastric-brooding frog that was eliminated by the amphibian chytrid fungus, advocates can avoid many of the conundrums of mammoths or thylacines or pigeons. But I’ll point out that we have not solved the chytrid problem, and Zoo Atlanta is like many zoos right now with large colonies of Panamanian golden frogs that cannot be reintroduced to the wild because of the fungus. Is the goal of gastric-brooding frogs forever in glass boxes, extant but in permanent quarantine, a conservation success?

Logistics and practicalities aside, there too are significant moral and ethical considerations at stake. Rather than try to articulate all those subtleties here, I’ll use this as an opportunity to recommend a fantastic book (that I use as a textbook in my conservation course). It is by ethicist Ben Minteer, at Arizona State University and Phoenix Zoo, entitled The Fall of the Wild: Extinction, De-Extinction, and the Ethics of Conservation (2019; Columbia University Press).

In my own personal opinion, I am grateful for the species we have left on the planet and I am saddened by all the losses—especially the more recent ones that clearly bear our fingerprints. I think our priorities should be directed toward what we have, especially because we are not yet achieving overwhelming successes in many cases. We know what to do and we know the outcome will be successful if we can muster the human will and resources. I’ll take certainty over an enormous gamble any day.

Some heavy stuff to think about as you enjoy the Zoo this fall season. Grab me if you see me and want to discuss, as I would love to hear your opinions on this complex topic!

Further reading:

The New York Times: https://www.nytimes.com/2021/09/13/science/colossal-woolly-mammoth-DNA.html

A few of the many relevant TED Talks (2013): there are a number of talks, both pro and con, in this series:

https://www.youtube.com/watch?v=XKc9MJDeqj0
https://www.youtube.com/watch?v=rUoSjgZCXhc
https://www.youtube.com/watch?v=ErexJkoDhGI
https://www.youtube.com/watch?v=DCnhQzwgP-A&t=679s

Joe Mendelson, PhD
Director of Research