Can genomics and genome editing assist in wildlife conservation?

Blog post by Caroline Mortelliti. See the video here for more information about the origins of the post. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License

ExtinctDodoBird

Facsimile of 1626 painting of the now-extinct dodo by Roelant Savery. Public domain image.

Our planet is in the midst of its sixth mass extinction, with loss of faunal and floral species at rates unseen since the extinction of the dinosaurs over 65 million years ago.¹ While extinction events can be naturally-occurring phenomena, the current mass extinction is of exceptional concern as it is driven by human activity. Today, some scientists think they have developed a solution to mitigate this extinction crisis: the de-extinction project. In this post, I comment on the strengths and weaknesses of this controversial solution.

What is paleogenomics & de-extinction?

Paleogenomics is an approach that allows whole genomes to be recreated from long-dead or extinct species. The practice includes obtaining the DNA of the extinct species, sequencing its genome, and matching the extinct DNA to the DNA of its closest living ancestor. Scientists may then edit the living ancestor’s genome to match that of the extinct genome, insert the newly edited DNA into a host stem cell, and grow an in vivo clone of the once extinct animal.²

However, the success of paleogenomics and de-extinction relies on the integrity of ancient DNA. Under ideal conditions, a sample of DNA can last a long time, potentially millions of years, but less ideal environmental conditions can hasten the degradation of DNA’s chemical bonds, or it can become contaminated with the DNA of other organisms, ruining the sample. Therefore, little gathered DNA is viable for palaeogenomics. As a result, de-extinction’s impact on conservation efforts is currently limited.

Genome Editing

The genome editing tool, CRISPR-Cas9 (CRISPR), can assist conservation genomics in a number of ways. First, CRISPR (see image below for an explanation of how it works) can help bring select animals back to life. More effectively, however, genome editing can tweak the genes of endangered species or species that have reproductive difficulty, so that their chances of survival are enhanced. Genome editing can also be used to lessen the invasive tendencies of destructive invasive species. For example, CRISPR can be used to introduce sterility genes in select members of invasive species and disease-carrying vectors, eventually lowering their population numbers and therefore enhancing  biodiversity.

CRISPR-Cas9-biologist

Guide to CRISPR-Cas9, produced by ‘J LEVIN W’. Reproduced under a Creative Commons Attribution-Share Alike 4.0 International license. Available online at: commons.wikimedia.org/wiki/File:CRISPR-Cas9-biologist.jpg

Advocacy for Genomic Approaches

Those who advocate for de-extinction and associated genome editing techniques are often geneticists and molecular biologists who are comfortable with the use of highly technoscientific approaches. By using technoscience to address the extinction crisis, advocates believe that wronged animals and ecosystems will receive their due justice. Additionally, and perhaps moreover, the extinction crisis presents a unique field of opportunity for making advancements in technoscience that could change the face of genetic engineering.

Biodiversity is recognized as a hallmark of a healthy ecosystem, and so many scientists feel they have a moral obligation to act to prevent and reverse loss of biodiversity. Paleontologist Michael Archer believes that since new technologies give us the capabilities to resurrect extinct species, we as humans have the “moral obligation” to right our wrongs and bring these animals justice. “If we’re talking about species we drove extinct, then I think we have an obligation to try to do this”. Alternatively, some critics claim the practice takes on new levels of ethical misconduct and hubris by challenging divine order. To this point, Archer rebuts: “I think we played God when we exterminated these animals”.³

Some scientists believe that de-extinction will increase biodiversity and thus the likelihood of finding natural compounds that can be used to develop pharmaceutical drugs. In some cases, advocates support de-extinction simply because it’s revolutionary. Bioethicist Hank Greely supports the de-extinction process having extensively studied its ethical and legal implications. “What intrigues me is just that it’s really cool. A saber-toothed cat? It would be neat to see one of those”.³

Challenges to de-extinction efforts

The de-extinction process can be interpreted as a threat to conservation efforts in two ways.

First, the de-extinction project distracts from the very successful and reliable conservation efforts that are currently in place, mainly by reallocating funds for de-extinction research.

Second, that de-extinction distracts younger generations from concerning themselves with conservation matters. The implementation of de-extinction practices might provoke a careless attitude among the public. If people believe that animals can always be ‘brought back’, then there would be little incentive for anyone to protect them from extinction in the first place. This attitude is dangerous, say conservationists. Furthermore, even more species could be saved if that money was put towards existing conservation efforts.

In summation, the money would be better spent supporting the programs that keep species from going extinct in the first place. “It’s better to spend the money on the living than the dead” says the lead author of one study, biologist Joseph Bennett.⁴

Conservation biologists and rewilding specialists raise another interesting objection against this application of genomics. They claim that reintroducing an animal into an environment that has changed since it was naturally abundant there is a risky endeavour. “Without an environment to put re-created species back into, the whole exercise is futile and a gross waste of money,” says environmental philosopher Glenn Albrecht.³

Arabian_oryx_(oryx_leucoryx)

Arabian oryx (Oryx leucoryx) in the Dubai Desert Conservation Area, UAE. Photograph by Charles J. Sharp. Reproduced under a Creative Commons Attribution-Share Alike 3.0 Unported license. Available online at: https://commons.wikimedia.org/wiki/File:Arabian_oryx_(oryx_leucoryx).jpg

One example of where rewilding has failed is with the Arabian oryx, a straight-horned antelope. A huge effort went into restoring the Arabian oryx in the wild, but after the animals were reintroduced into their previous habitat in 1982, they met a quick demise from poachers, disease, and mating complications. “We had the animals, and we put them back, and the world wasn’t ready”.³ Returning a species to its natural environment requires the coordination of multiple scientific and non-scientific actors.

Moving Forward

Many scientists have significant concerns with using the de-extinction project as a legitimate wildlife conservation solution.⁵ De-extinction practices do not address pressing ecologic matters; resurrecting one animal will not keep another from meeting the same fate.

However, while de-extinction may not be a solution, through genome editing some species could be responsibly and successfully re-introduced. De-extinction is in many respects a luxury, an exciting idea for scientists to pursue, to be explored so long as it does not interfere with or compromise current conservation efforts.²

The concepts of de-extinction and genomic engineering reveal human’s insatiable need to demonstrate a mastery of living things.

How far will we allow the technosciences to develop? Geneticist George Church once remarked, “Maybe some people thought polio vaccines were a distraction from iron lungs”.³ It is difficult for us predict what might be an obstacle, and what might be a cure.

Sources referenced:

1. Center for Biological Diversity (2017) “The Extinction Crisis”.

2. Sandler, R. (2013) “The Ethics of Reviving Long Extinct Species”, Conservation Biology, Vol. 28, No. 2, pp. 354–360.

3. Zimmer, C. (2013) “Bringing them back to life”, National Geographic magazine.

4. Bennett, J. et al. (2017) “Spending limited resources on de-extinction could lead to net biodiversity loss”, Nature: Ecology & Evolution, Vol. 1: 0053.

5. Fischer, F. (2003) Reframing Public Policy: Discursive Politics and Deliberative Practices. Oxford University Press.

See also:

Brand, S. (2013) TED talk: “The dawn of de-extinction. Are you ready?”

Revive & Restore project website

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