While the idea that de-extinction may spark interest in conservation—more precisely, in funding conservation research—is attractive, it also highlights an important weakness in the present strategy to fund de-extinction research. Today, this research is being performed by scientists on species that the scientists find interesting. However, private individuals are being asked to fund the work. Just as the lion’s share (pun intended) of conservation funding goes to the most charismatic of endangered species, species will probably be selected for de-extinction based on their public appeal. People are likely to be far more interested in dodos and Steller’s sea cows than they are in extinct kangaroo rats and land snails, although kangaroo rats and land snails are arguably more critical to the stability of their ecosystems than either dodos and Steller’s sea cows were to theirs. Ultimately, our partiality toward charismatic megafauna will lead to a taxonomic imbalance among de-extinction projects that is not unlike the imbalance that exists in conservation work.
If de-extinction is to become a genuine weapon to be used in the war against contemporary extinctions, all sectors of society—and not just scientists—will need to work together to identify the resources to make it happen.
UNEXTINCT SPECIES HAVE NOWHERE TO GO
Unfortunately, many species that are candidates for de-extinction have no habitat in which to live. The more people there are in the world, the less space there is for other species. Deforestation and illegal hunting are significant problems in many parts of the world. If these are the problems that led to extinction in the first place, these problems must be resolved before that extinction can be reversed.
Some species require more space than it might be possible to find. Gray wolf populations are booming in Yellowstone National Park, where they are protected from humans. The park provides nearly 9,000 square kilometers of space for wolves, but this is not enough. As the wolves jostle for territory and dominance, they expand beyond the park’s borders. When they get out, they cause mayhem and get shot. When dominant wolves get shot, it upsets the pack structure and dynamics. Gray wolves cannot quite come to a sustainable equilibrium in a space the size of Yellowstone.
Finding sufficient amounts of suitable habitat will certainly present a challenge for some de-extinction projects. This should not, however, preclude further assessment of the suitability of other species for de-extinction. Nor should it deter efforts to improve habitat by removing invasive species or enforcing anti-poaching or anti-deforestation laws. On the contrary, highlighting this problem in the context of de-extinction may act as a beacon for new investment and new solutions, which would also benefit existing conservation projects.
RELEASING UNEXTINCT SPECIES WILL DESTROY EXISTING ECOSYSTEMS
To this concern, I respond with an emphatic “maybe.” Certainly, a thorough assessment of the environmental impact of releasing new species into the wild should be done before a de-extinction project begins. Assuming the candidate species for de-extinction is an animal, the assessment should include analyses of what and how much it is likely to eat, with which other species it will compete for resources, where and when it will sleep, by what means and how far it will move, what will eat it and what are the consequences of it being eaten, whether it will act as a vector for disease, and what effect it will have on nutrient cycling, pollination, the microbial community, and so forth. Regardless of how thorough and careful these assessments are, there will be unanticipated interactions between species and unanticipated consequences to the ecosystem. This is unavoidable. When the species went extinct, the ecosystem in which it was once a part evolved to accommodate its absence. Other species, sometimes even invasive species, moved in. Reintroducing the extinct species may upset the existing dynamics within that ecosystem, but to claim that that ecosystem will be “destroyed” might be going too far. Yes, species introductions change ecosystems—that is often the point of the introduction. To this end, a risk assessment will not ask whether an ecosystem would change (it would), but how it would change, how other species would be affected, and whether the reintroduced species would be sustainable within that ecosystem.
Completing such an assessment is likely to reveal that some species are poor candidates for de-extinction. Some species would be too destructive to fit within the confines of today’s people-dominated world; imagine sixteen-foot-tall short-faced bears wandering around downtown Los Angeles. Some species simply have nowhere to go; the Yangtze River dolphin cannot be placed back into its natural habitat unless there is dramatic improvement in the water quality of the Yangtze River. Some species may require more long-term investment than it is possible to secure. We may find that so little is known about the behavior and ecology of some species that the risks of environmental catastrophe far outweigh the benefits of their return to the ecosystem.
If a reintroduction does have catastrophic consequences, we could simply remove that species from the ecosystem using whatever means necessary. Re-extinction is certainly an extreme tactic, but it calls on expertise that we already know we have. Of course, it may not be that simple. Once an organism is released, it will start to affect the ecosystem into which it has been introduced. It’s doubtful that everyone will agree about whether these changes are good, or even acceptable. Society as a whole will have to decide whether removal is necessary, and this will not be an easy decision to make.
Consider the example of beavers in Great Britain. Until recently, beavers were extinct in Great Britain. Beavers were driven to extinction in Great Britain some 400 years ago by humans, who valued beaver fur and medicinal glands and loathed beavers. Beavers are destructive; they cut down trees and use these to build dams, which cause rivers and streams to flood. Dead beavers were better beavers, at least to sixteenth-century Britons, and so beavers disappeared. Then, in 2006, beavers were discovered living along the River Tay in Scotland. In early 2014, a family of wild beavers was spotted in Devon, in the southwest of England, playing in the River Otter. It is believed that both of these beaver populations were established after deliberate and illegal release from private collections.
Along the Rivers Tay and Otter, residents differ widely in how they feel about the beavers. Some residents are quick to identify the positive impacts they’ve seen on the environment since the beavers reappeared. They point out that, by building dams along the rivers, the beavers have created new habitat for frogs that lay their eggs in the shallow, slow-moving ponds formed by the dams. These frogs and their eggs are, in turn, an important food source for insects, birds, and fish, which some residents claim have increased in abundance since the beavers’ return. The beaver dams have also begun to reestablish local wetlands, which the residents hope may help to control flooding along the rivers. Other residents, however, dislike the beavers. These residents point out that beaver dams block migration routes used by salmon and trout, and may actually increase rather than mitigate flooding, with devastating consequences for riverside farms.
While beavers, fish, and agriculture coexisted in Britain for centuries, the British countryside has changed considerably over the last 400 years. Thanks to these changes, it is not at all clear that coexistence can resume.
So what to do? Should the illegally released beavers be removed from the British countryside, or should beavers be introduced to even more rivers? This has been a difficult question to answer. As a member of the European Union, Britain is under pressure to reintroduce native species that have been driven to extinction locally. The wild-living beavers may, in fact, already qualify for legal protection under EU laws. Within Britain, England, Scotland, and Wales get to decide for themselves what to do within their borders, and there is no consensus. Wales is considering allowing beavers to be introduced into the Welsh countryside, while the English government has established an official program to capture the beavers along the River Otter and remove them to captivity. Along the River Tay in Scotland, some 300 beavers now make their homes. The Scottish government is set to decide, soon, whether they get to stay.
The example above highlights yet another significant challenge that society will need to resolve if de-extinction is to move forward: when is it clear that a de-extinction experiment has failed? With beavers, the environmental impacts of release can be inferred from habitat in which the beavers still live. This will not be true when the organism to be released is completely extinct and, consequently, the risk that it all goes horribly wrong will be, admittedly, greater.
I want to circle back to the beginning at this point and restate something I said in the first pages of this book. While re-extinction is certainly an option, and one that quells the deepest fears of some de-extinction skeptics, I worry that people might resort to this drastic measure too quickly. Interactions between species may take years to develop. Ecosystems into which a resurrected species is introduced may become destabilized initially and only much later re-establish the interactions between species that were the goal of the de-extinction project. These experiments will take time, and I hope that we can be patient. It is natural, however, to fear what we do not know and cannot predict. Being patient will not be easy.
Concern about the appropriateness of hands-on environmental stewardship is not unique to de-extinction. Conservation strategies can be thought of as a continuum between entirely managed ecosystems (think “gardening”) and allowing nature to fend for itself (think “preserving”). De-extinction is a disruptive strategy and, as such, requires some amount of gardening. However, like other disruptive strategies—including rewilding, managed relocation, and island restoration—de-extinction can play a role across nearly the entire continuum. Some species will require constant gardening, while others will require little to no intervention to be sustainable once established. Regardless, all disruptive strategies are inherently risky, as there is always a chance that a heavy human hand may do more harm than good. Purely preservationist strategies are, however, also risky. What if sufficient habitat can’t be preserved? What if species do not re-establish populations in the habitat that is preserved? Few habitats have avoided completely the effects of human population growth, suggesting that, at some level, intervention has already occurred. Further intervention may be required simply to reduce the damage that has already been done.
Island restoration projects, such as two that are taking place off the coast of Mauritius, are proving that intervening can work. On Round Island and Ile aux Aigrettes, conservation biologists are working to remove invasive species and re-establish populations of native species. But there are problems. Native plants are slowly being replaced by invasive plants in the absence of the extinct giant tortoises that once thrived on the islands. The native plants grow slowly and close to the ground and have small tough leaves that are difficult for tortoises to eat. They also fruit when grasses—a main source of food for tortoises—are not abundant, which increases the likelihood that hungry tortoises would disperse their seeds. In the absence of giant tortoises, nonnative plants have outcompeted the tortoise-adapted native plants, many of which are now on the brink of extinction.
To restore the missing interactions between native plants and giant tortoises, the research teams introduced different species of giant tortoises that still survive in other parts of the Indian Ocean, hoping that these giant tortoises would functionally replace the extinct Mauritian giant tortoise. The introduced giant tortoises immediately took to their new habitat, preferring to graze on the non-native plants that lacked defenses against tortoise herbivory. They also ate the fruits of native species. Stands of ebony, which had struggled to survive in the absence of a large herbivore to disperse its seeds, have started to appear throughout the Islands.
IF DE-EXTINCTION IS POSSIBLE, THE RATE OF EXTINCTION WILL INCREASE
This moral hazard argument presents a horrible view of people. It assumes that that at the slightest (and I mean slightest) hint of a quick fix, no matter how not-so-quick and not-quite-a-fix it is, people will give up trying to preserve endangered species. Sure, legislation to protect endangered species is complicated, confusing, sometimes misguided, and too often out of date. But, it is hard to imagine that people who care about biodiversity conservation would suddenly stop doing so should de-extinction become possible.
Of course, there are many people who simply don’t prioritize biodiversity conservation, and others who have some stake in seeing species removed from protection. In these cases, one might imagine how the idea of de-extinction might be manipulated to further a specific political agenda. The notion that politics or big business might use biotechnology to manipulate rules, regulations, and public sentiment is, of course, not unique to de-extinction.
WE ARE “PLAYING GOD”
As an epigram to the first edition of the Whole Earth Catalog in 1968, Stewart Brand wrote, “We are as gods and might as well get good at it.” Like many of the ideas that motivate Stewart, this line, which he conceived while reading anthropologist Edmund Leach’s book A Runaway World, was meant to make people imagine, with bold optimism, a future that was different, pleasant, and full of wonder. But, he did not want them to stop there. Stewart wanted to motivate people to act, using that bold enthusiasm, to make real the future that they had just imagined.
Stewart’s issue with science and society, then and now, is their deference to the status quo. Their detachment. His argument is simple and positive: we can make a better future, but not by standing by and waiting for it to happen. We—everyone—must participate. It is our responsibility to use our intelligence and our advanced technology for good.
The “playing God” argument is not one that that has emerged in response to de-extinction but, instead, is an argument that arises frequently in response to technology that is new or not well understood. This argument can be religious, but it is often a metaphorical accusation—“playing God” may simply mean using powerful tools without understanding the full implication of those tools.
In the specific case of de-extinction, the accusation of playing God concerns human manipulation of nature. By engineering new organisms, by altering the structure of biological communities, and by altering the course of today’s extinction trajectory, we are messing with things that we simply don’t understand and therefore probably shouldn’t be messing with. Importantly, de-extinction does not mark the beginning of human manipulation of nature. With the earliest attempts at domestication of gray wolves in Europe some 30,000 years ago, our species began manipulating the genetics of other organisms to our advantage. Most of the food we eat has been genetically engineered—albeit by breeding and not by genome editing—to suit our tastes and to meet the growing demand for more. Species introductions, whether purposeful or accidental, have been happening since we first built boats and learned how to navigate from one place to another. And the extinction trajectory on which we are heading is, arguably, itself human induced.
I believe that what motivates this argument in the case of de-extinction is the fear of losing control. This is a reasonable concern. It is, however, a concern that should be expressed and addressed rationally, taking advantage of the scientific process.
THE PRODUCT OF DE-EXTINCTION WON’T BE THE SAME THING AS THE ORIGINAL SPECIES
That is correct. It won’t be the same.
In Stewart Brand’s half of his written debate with Paul Ehrlich, he writes: “If it looks like a passenger pigeon and flies like a one, is it the original bird?” My answer is no, it’s not the same, and by this point in the book it should be clear why my answer is no. Crucially, however, I don’t care that it’s not the same thing as the original, and I’m pretty sure that Stewart doesn’t care, either.
The task ahead is not to make perfect replicas of species that were once alive. First, it is technically not possible to do so and is unlikely ever to become technically possible to do so. Second, there is no compelling reason to make perfect replicas of extinct species. The goal of de-extinction is to restore or revive ecosystems, to reinstate interactions between species that no longer exist because one or more o
f those species are extinct. We don’t need to create exact replicas of extinct species to achieve this goal. Instead, we can engineer species that are alive today so that they can act as proxies for extinct species. We can revive adaptations from the past—adaptations that arose by chance and were refined by evolution—in species that are still alive today.
In fact, there is no reason to restrict this technology to de-extinction. If living species are threatened by a lack of diversity or by an inability to adapt quickly enough to a rapidly changing climate, why not facilitate their adaptation as well?
The American chestnut tree is a great example of the power of genome engineering in conservation. Around the year 1900, the accidental importation of a fungus from Asia wiped out nearly every single American chestnut tree. The airborne fungus kills the tree by forming cankers in the bark that cut off the flow of nutrients from the ground. New shoots may grow from surviving roots, but none of these escapes the deadly fungus. Thanks to genetic engineering, American chestnuts are now on the verge of making a dramatic comeback into the eastern deciduous forests of North America. Led by Bill Powell and Charles Maynard of the State University of New York in Syracuse, the American Chestnut Research and Restoration Project has genetically engineered several new strains of American chestnut that are increasingly resistant to the fungus. In 2006, this team planted the first fungus-resistant chestnut seeds in the wild. Today, there are more than one thousand genetically modified American chestnut trees growing in the state of New York.
How to Clone a Mammoth Page 22