Print

A cynical move is underway to promote a new, powerful, and troubling technology known as “gene drives” for use in conservation

1. The perils of planned extinctions
2. Argument builds around a genetic tool that can erase an annoying species

1. The perils of planned extinctions

Claire Hope Cummings
Project Syndicate, Sept 6, 2016
https://www.project-syndicate.org/commentary/gene-drive-conservation-risks-by-claire-h--cummings-2016-09?referrer=/YJvmtosOVo
[links to sources at the URL above]

A cynical move is underway to promote a new, powerful, and troubling technology known as “gene drives” for use in conservation. This is not just your everyday genetic modification, known as “GMO”, it is a radical new technology, which creates “mutagenic chain reactions” that can reshape living systems in unimaginable ways.

Gene drives represent the next frontier of genetic engineering, synthetic biology, and gene editing. The technology overrides the standard rules of genetic inheritance, ensuring that a particular trait, delivered by humans into an organism’s DNA using advanced gene-editing technology, spreads to all subsequent generations, thereby altering the future of the entire species.

It is a biological tool with unprecedented power. Yet, instead of taking time to consider fully the relevant ethical, ecological, and social issues, many are aggressively promoting gene-drive technology for use in conservation.

One proposal aims to protect native birds on Hawaii’s Kauai Island by using gene drives to reduce the population of a species of mosquito that carries avian malaria. Another plan, championed by a conservation consortium that includes US and Australian government agencies, would eradicate invasive, bird-harming mice on particular islands by introducing altered mice that prevent them from producing female offspring. Creating the “daughterless mouse” would be the first step toward so-called Genetic Biocontrol of Invasive Rodents (GBIRd), designed to cause deliberate extinctions of “pest” species like rats, in order to save “favored” species, such as endangered birds.

The assumption underlying these proposals seems to be that humans have the knowledge, capabilities, and prudence to control nature. The idea that we can – and should – use human-driven extinction to address human-caused extinction is appalling.

I am not alone in my concern. At the ongoing International Union for the Conservation of Nature (IUCN) World Conservation Congress in Hawaii, a group of leading conservationists and scientists issued an open letter, entitled “A Call for Conservation with a Conscience,” demanding a halt to the use of gene drives in conservation. I am one of the signatories, along with the environmental icon David Suzuki, physicist Fritjof Capra, the Indigenous Environmental Network’s Tom Goldtooth, and organic pioneer Nell Newman.

The discussions that have begun at the IUCN congress will continue at the United Nations Convention on Biological Diversity in Mexico this December, when global leaders must consider a proposed global moratorium on gene drives. Such discussions reflect demands by civil-society leaders for a more thorough consideration of the scientific, moral, and legal issues concerning the use of gene drives.

As I see it, we are simply not asking the right questions. Our technological prowess is largely viewed through the lens of engineering, and engineers tend to focus on one question: “Does it work?” But, as Angelika Hilbeck, President of the European Network of Scientists for Social and Environmental Responsibility (ENSSER) argues, a better question would be: “What else does it do?”

When it comes to the GBIRd project, for example, one might ask whether the “daughterless mouse” could escape the specific ecosystem into which it has been introduced, just as GMO crops and farmed salmon do, and what would happen if it did. As for the mosquitos in Hawaii, one might ask how reducing their numbers would affect the endangered hoary bat species.

Ensuring that these kinds of questions are taken into account will be no easy feat. As a lawyer experienced in US government regulations, I can confidently say that the existing regulatory framework is utterly incapable of assessing and governing gene-drive technology.

Making matters worse, the media have consistently failed to educate the public about the risks raised by genetic technologies. Few people understand that, as MIT science historian Lily Kay explains, genetic engineering was deliberately developed and promoted as a tool for biological and social control. Those driving that process were aiming to fulfill a perceived mandate for “science-based social intervention”.

Powerful tools like genetic modification and, especially, gene-drive technology spark the imagination of anyone with an agenda, from the military (which could use them to make game-changing bio-weapons) to well-intentioned health advocates (which could use them to help eradicate certain deadly diseases). They certainly appeal to the hero narrative that so many of my fellow environmentalists favor.

But the fact is that we have not created the intellectual infrastructure to address the fundamental challenges that gene drives – not to mention other powerful technologies – raise. And now we are supposed to suspend our critical faculties and trust the techno-elites’ promise to use gene drives responsibly in the service of seemingly positive environmental goals. No open public discussion is needed, apparently. But why should we blindly believe that everything is under control?

In my view, the focus on using gene-drive technology for conservation is a ruse to gain public acceptance and regulatory cover. Why expose something to public scrutiny and possible restraints when you can usher it in through the back door by pretending it will do some good? The risks are too obvious for gene-drive advocates to risk talking about them.

In my 20-plus years of researching and reporting on transgenic technologies, I thought I had seen the worst of the false promises and hype that they engender. But gene drives are unlike anything we have witnessed, and amount to the ultimate test of our self-control. Can we really trust science to guide us, or do we recklessly throw in our lot with technological “silver bullets” as the way forward?

Fortunately, we still have a choice. The fact that gene drives can change the basic relationship between humanity and the natural world is both a challenge and an opportunity. We can do now what we should have done a long time ago, with regard to both nuclear and transgenic technologies: start paying more attention to the dangers of human ingenuity – and more respect to the genius of nature.

2. Argument builds around a genetic tool that can erase an annoying species

By Ron Meador
MinnPost, 7 Sept 2016
https://www.minnpost.com/earth-journal/2016/09/argument-builds-around-genetic-tool-can-erase-annoying-species

What if scientists could wipe out an entire species of malaria-carrying mosquito across sub-Saharan Africa, and other tropical regions of the world, with a bit of genetic editing that would drive its swarms to extinction in just a few years?

Or, with the same tool, stop the spread of Lyme disease by eliminating the white-footed mice that serve as reservoirs for that parasite? Maybe rescue portions of the Galapagos by rubbing out invasive rats?

If this sounds like the stuff of futuristic fantasy fiction to you, you have missed the coverage gathering this summer around the promise and perils of “gene drive” technology, a simplified approach to genetic engineering with a clear capability to erase entire species within just a few generations. (The target insect’s or rodent’s generations, that is, not human ones.)

The topic is front and center this week at the World Conservation Congress in Hawaii, the quadrennial meeting of the International Union for the Conservation of Nature. Delegates there have voted overwhelmingly to call a temporary halt to development of gene drive techniques until the world has had to chance to reflect upon the many ways in which it could go way wrong.

That action follows publication of an open letter [PDF] signed by such luminaries as Jane Goodall, David Suzuki and Fritjof Capra declaring that gene drive technology, “which has not been tested for unintended consequences nor fully evaluated for its ethical and social impacts,” brings humanity to “a moral and ethical threshold that must not be crossed without great restraint”.

Most mainstream media coverage, however, has carried the sort of cheerful, gee-whiz tone of Saturday’s Wall Street Journal piece headlined, “Mosquitoes are deadly, so why not kill them all?”

There is no shortage of sound answers to that question, but before turning to them let’s talk a bit about the science that has made it necessary and really rather urgent. Since mosquitoes are the primary near-term targets of the technique, they offer a fine illustration.

Making mosquitoes all male

When a male and female mosquito mate, each of their offspring has a 50 percent chance of being female and a 50 percent chance of being male. This is more or less the same for all traits passed down genetically by all species, plant and animal, that reproduce sexually.

With the development of genetically modified crops, like pest-resistant corn, the goal was to insert new genetic traits within the organism. The gene drive method, in contrast, uses a simplified editing technique to make sure that only one version of a trait, like gender, can be passed along.

British scientists have demonstrated, at the petri-dish level, that it is possible to modify the chromosomes of a malaria-carrying Anopheles mosquito so virtually all of the offspring are male.

This carries a dual advantage for disease control: Only females can inject the malaria parasite with their bites. And an all-male population — already shown to be achievable in just a few generations of the fruit fly, that workhorse of testing for genetic inheritance — can no longer reproduce itself.

This is not the only high-tech approach under consideration right now for advanced mosquito/malaria control. It’s not to be confused, for example, with a work on getting insects to carry new genetic material that can resist or kill a virus like Zika. Or torpedoing population growth by introducing insects made sterile with radiation, or outfitted with bacteria that can be passed along to offspring with lethal effects.

Those tools have a lot of potential and have inspired their own controversy. But in potential impact they don’t approach the gene drive with its simple, quick capacity for engineered extinction.

Problem is — assuming that something might just possibly go wrong — it’s an extinction mechanism without a kill switch.

To its credit, the Journal story acknowledges (if only glancingly) that there are arguments for going slow with the gene drive approach to fighting Zika, malaria and other insect-borne diseases. So does an earlier piece (with a highly similar tone and headline) in Time magazine.

The case for precaution

They can be grouped in a few categories, and are discussed in more detail in this fine piece of a month ago in the journal Science:

* Mosquitoes play key roles in ecosystems, such as providing food for bats and other insectivores, and “scientists have minimal experience engineering biological systems for evolutionary robustness”.
* It’s possible that a gene drive might not distribute the intended trait throughout a target population, or might find its work blocked by a naturally occurring mutation, or might spread the trait to nontargeted species.
* It’s also possible that a gene drive could stimulate other unforeseen evolutionary responses over a longer term in both target and nontarget species.
* And, again, the ability to redress any of these unintended consequences could be sharply limited by the lack of reliable reversal mechanisms.

Even scientists championing gene-drive technique recognize and discuss these limitations and risks, but generally as little hurdles to be crossed somewhere down the road.

For example, the entomologist Zach Adelman of Texas A&M, who is trying to engineer a males-only rewrite to the chromosomes of the Zika-carrying Aedes aegypti mosquito, told the Journal that he sees the technology as “an all-powerful tool that will win the war for us, but that is exactly the sentiment that people felt when things like DDT first came along. ... It’s good to be optimistic. But we need to be realistic as well. “

On the other hand, he says frankly that, “I think it is our moral duty to eliminate this mosquito.”

And at the moment, that notion of a moral imperative in favor of rapid deployment rather than precautionary restraint seems to be dominating the conversation among many scientists — the views of Jane Goodall and the IUCN notwithstanding — and other powerful actors including Bill Gates, whose foundation has invested many millions in both the development of gene drive techniques and their eventual application.

Speaking to a Bloomberg reporter in June, Gates acknowledged that “there’s a still a fair amount of work to be done” and that “nothing is ready to be deployed today,” but these points were secondary to “my basic belief ... that children dying of malaria is a bad thing, and that we should be able to meet these objections”.

“Gates says he hopes to see gene editing used against HIV. His foundation has funded older gene-editing efforts against HIV, which were less efficient than [the new gene drive tool]. ‘HIV is still a lifelong disease, and any type of cure approach or some sort of way that you’d protect somebody on a lifelong basis, that would be invaluable, but that’s at a very early stage.’”

And as a former Namibian health minister, Richard Kamwi, told Time:

“A malaria vaccine has been 10 years down the road for 25 years. We need something now, before the tools we have stop working. I want to call on all the researchers and say that where they have been walking, they must start running. Where they have been jogging, they must start sprinting.”