Received: 26 January 2021 Revised: 18 March 2021 Accepted: 26 March 2021
Editing the wild
William M. Adams1Kent H. Redford2
1University of Cambridge, Cambridge, UK
2Archipelago Consulting, Portland, Maine, USA
Kent H. Redford, Archipelago Consulting, Portland,ME 04112, USA.
Article impact statement: Synthetic biology is being used to edit genomes of wild species for ag riculture and human health. Conservation science must get involved.
GENE EDITING FOR CONSERVATION
A growing conservation science literature is exploring possi-
ble conservation applications of gene editing (e.g., Phelps et al.,
2019; Piaggio et al., 2016; Redford et al., 2019). Proposals
mainly focus on 2 approaches. First, to change the genomes
of species of conservation concern to enhance their ability to
survive threats like disease, for example, amphibians threatened
by chytrid fungus, or anthropogenic environmental changes, for
example, reef-building corals threatened by warming oceans.
Second, to change the genomes of species that threaten the sur-
vival of rare or endemic species, for example, invasive species
on oceanic islands.
Most discussion of conservation applications of gene edit-
ing is still more or less speculative, discussing the use of newly
developed tools and procedures or wishfully hoping for novel
solutions to intractable conservation problems. There is no seri-
ous funding available for such conservation applications, be
they blue-sky or practical. Development and application are
much more advanced in human health, veterinary science, and
agriculture, where gene editing is an increasingly mainstream
There are a small number of serious proposals for apply-
ing editing and related technologies to conservation problems,
suggesting that signiﬁcant funding might become available. For
example, an international partnership is developing a gene drive
to rid oceanic island of invasive house mice (GBIRD, 2019).
There are also efforts to apply gene editing to de-extinction (e.g.,
Novak, 2018), although the conservation relevance of this strat-
egy is more speculative.
There is an extremely important debate to be had about the
application of gene editing in conservation (Redford & Adams,
2021). Risks and beneﬁts are already being explored in the con-
servation science literature (e.g., Sandler, 2019), and in the inter-
national policy realm (e.g., Redford et al., 2019).
ENGINEERING WILD SPECIES
However, there is a signiﬁcant blind spot in much of the dis-
cussion to date of possible conservation applications of syn-
thetic biology (whether advocating them or recommending that
they are not used). This relates to 2 assumptions: ﬁrst, that the
genetic engineering of nondomesticated species is something
that may or may not happen in the future; second that those
decisions will be taken by conservation scientists and practition-
These assumptions have been an explicit or implicit feature of
meetings in which we have participated. They reﬂect profoundly
mistaken understanding. The question of whether wild species
(meaning those that are free to interact with other species out-
side of direct human control) should or should not be genet-
ically engineered is not something that might happen in the
future. It has already been done in a small number of cases and
is close to happening in several more. And decisions about those
deployments are not being informed by the views of conserva-
tion scientists at all.
The leading ﬁelds in which the genomes of free-living non-
domesticated species have been engineered are agriculture (pest
control) and public health (disease vector control). Genetically
engineered insects and other crop pests include pink boll worm
(Pectinophora gossypiella), fruit ﬂies of various species (Drosophila),
and screwworm ﬂies (Cochliomyia hominivorax). Experimental
releases of the diamondback moth (Plutella xylostella)have
already taken place in an experimental ﬁeld in the American
state of New York––ecologically isolated, though not in a bio-
containment facility (Shelton et al., 2020).
Microbial species in the microbiomes of both insects and
plants are also being genetically modiﬁed to control agricul-
tural pests and enhance crop growth. Species in the honeybee
microbiome are being genetically modiﬁed to address colony
collapse disorder (Paxton, 2020). Microbes are being engineered
Conservation Biology. 2021;1–3. © 2021 Society for Conservation Biology 1wileyonlinelibrary.com/journal/cobi
2ADAMS ET AL.
to promote their capacity to cause disease in wild agricultural
pests (Azizglu et al., 2020). Genetically modiﬁed microbes are
being developed for application in bioremediation and wastew-
ater plants (Dvorak et al., 2017). Microbes that are part of the
human microbiome are being engineered and will inevitably join
their wild relatives through leakage from human bodies.
Genetic engineering of wild species is also well advanced in
human public health. There is a signiﬁcant investment in genet-
ically modifying mosquito vectors for malaria, dengue, and Zika
(Jones et al., 2021). In the case of Aedes aegypti, over a billion
genetically modiﬁed mosquitoes have been released in Brazil,
Panama, the Cayman Islands and release in Florida has been
approved (Oxitec, 2021).
Genetically modiﬁed ﬁsh are already in extensive production,
mostly in contained pens. But ﬁsh have escaped and in Norway
have bred with wild salmon and trout (Karlsson et al., 2016).
Genetically altered trees, so far poplar and eucalyptus, have also
been developed and planted (Chang et al., 2018).
Finally, though not wild species, gene-edited crop species
have been widely planted in an increasing number of countries.
The modiﬁed genomes in crop species are subject to evolution-
ary forces, including horizontal gene transfer and movement
into wild relatives or other plant species growing near agricul-
tural ﬁelds. Such movement across species boundaries appears
to be quite common (e.g., cotton, sunﬂower, rice, and papaya,
Vázquez-Barrios et al., 2021) leading to the reasonable assump-
tion that it will continue to happen with future genetically mod-
GENE EDITING AND CONSERVATION
The immediate ecosystems in which most of these interven-
tions have taken place are agricultural ﬁelds, forests, gardens,
or built-up areas. Some conservationists, tightly focused on the
protection of relatively undisturbed ecosystems globally, might
be tempted to dismiss genetic interventions in extensively trans-
formed ecosystems of this kind as unimportant. This would be
a mistake, for 3 reasons.
First, gene editing of free-moving species for agricultural or
health purposes will have biodiversity impacts (Redford et al.,
2019). Nature is not limited to the earth’s remining biodiverse
areas. Agricultural ﬁelds and other transformed habitats are also
ecosystems. They are connected ecologically and through gene
ﬂow to other ecosystems, including some that are of the high-
est conservation importance. The release of organisms with
engineered genomes into unbounded spaces offers the risk of
spread, and gene introgression. Experiments in agriculture and
public health have ecological and conservation implications.
Second, the battles that are beginning on agricultural and
health applications to edit wild species will shape the land-
scape of funding, regulation, and public opinion when conser-
vation applications themselves are brought forward (Redford
& Adams, 2021). Nonconservation applications will create the
framework within which conservation applications will also be
judged by public opinion. Conservation does not exist in a bub-
ble. Debates about what is best for wild biodiversity will not
remain independent of public debates about the risks and ben-
eﬁts of gene editing, particularly within the agriculture, biotech,
or pharmaceutical industries.
Third, the use of genetic engineering potentially undermines
conservation’s claim to be preserving nature. Conservation
practice is widely built on a distinction between naturalness (a
state of nature that needs to be protected, typically described
as “wild” or “pristine” nature) and artiﬁciality (the impact of
human technologies and demands on the biosphere, from which
nature needs to be protected). Conservation already uses many
technologies to manage populations and ecosystems. Yet, as a
technology, genetic engineering is utterly novel. Its use to “save
nature” therefore potentially exposes conservation to popu-
lar understandings of genetic engineering as “unnatural.” Such
ideas, often using the emotive labels, such as “Frankenstein tech-
nologies” were important in environmentalist critiques of genet-
ically modiﬁed crops in the 1990s. Such ideas of the “unnatu-
ral” character of gene editing are potentially highly effective in
campaigning and are likely to shape public understanding of,
and reaction to, genetic engineering for conservation purposes
just as it will for commercial applications. Evidence for this can
already be found in some negative reaction to the use of genetic
engineering to create blight-resistant American Chestnut (Cas-
tanea dentata) by the insertion of a gene from wheat which pro-
duces an enzyme with antifungal properties (Newhouse & Pow-
ell, 2021; Smolker & Peterman, 2019;Taylor,2018).
ENGAGING WITH GENETIC
Both supporters and detractors of gene editing of free-living
species, including “wild” or nondomesticated species, need to
recognize both that such releases have already taken place and
that more are planned as gene editing technology becomes
mainstream in ﬁelds like agriculture and human biology and
biotechnology. The scale and pace of the expansion of the syn-
thetic biology revolution globally (led by China and the United
States, but with many other countries following close behind) is
While the category of “conservation applications” or “con-
servation synthetic biology” may seem useful in debates in con-
servation journals and webinars, in practice, all genetic engineer-
ing of free-living species is important to the future of life on
Earth, and to the conservation organizations and scientists who
work to secure it. Nonconservation gene editing applications
may be taking place “off-stage” from a conservation perspec-
tive, but they will be critical in creating the framework and pub-
lic response within which conservationist applications will be
Conservation science has expanded its horizon repeatedly
in response to evolving understanding from within the disci-
pline as well as criticism from those outside. It has embraced
economics, psychology, and is engaging with anthropology and
political ecology. It has learned to open up to informed dis-
cussions of poverty, justice, and Indigenous and local cul-
tures. Now, it needs to expand again, to engage with the
CONSERVATION BIOLOGY 3
wider debates about gene editing and synthetic biology. Genetic
technologies are transforming scientiﬁc ﬁelds and industries
from biotechnology and pharmaceutics to food production and
public health. Without doubt, they will also transform the natu-
ral world, both directly and indirectly. They may also transform
conservation practice in the years to come, and these changes
need careful, informed, and wide debate (Sandler, 2019).
Conservation scientists and practitioners urgently need to
develop the capacity and desire to understand the implications
of gene editing of free-living species, both those of conservation
concern and those that are not yet rare, and the impacts of gene
editing on both intact and human-transformed ecosystems.
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How to cite this article: Adams WM. & Redford KH.
Editing the wild, Conservation Biology. 2021;1−3.