The Right to Exist: When Science Considers Erasing a Species to End Suffering

When does saving lives justify erasing an entire species from Earth?

A new international study published in Science tackles this thorny ethical question as genetic engineering technologies make deliberate extinction increasingly possible. The research examines three specific cases where scientists could potentially wipe out harmful species—and concludes that such extreme measures might be justified, but only under the rarest circumstances.

The study focuses on creatures that cause immense suffering: flesh-eating screwworm flies, malaria-carrying mosquitoes, and invasive rodents that are driving island bird species toward extinction. Each presents a different ethical puzzle about the value of species versus the harm they inflict.

The Case for Erasing the Screwworm

The New World screwworm stands as the leading candidate for deliberate extinction. This parasitic fly lays eggs in wounds and mucous membranes of warm-blooded animals. The larvae then burrow into living flesh, literally eating their hosts alive and causing bacterial infections that often prove fatal.

Already eliminated from North America and Central America through traditional methods, screwworms persist across South America where eradication efforts prove too costly. But new genetic techniques could change that equation dramatically. Scientists have developed genetically modified strains that eliminate female larvae unless exposed to tetracycline, making population control far more efficient and cost-effective.

The suffering is undeniable. From livestock losses threatening food security to occasional human infections that result in slow, agonizing deaths, screwworms inflict tremendous harm. Yet even this case isn’t clear-cut.

Where Philosophy Meets Pest Control

The research reveals a fascinating tension in how we value different species. While Western conservation philosophy typically argues that all species possess equal intrinsic value, the study notes that willingness to eradicate certain creatures “might be influenced by a dislike of parasitism or a disregard for species perceived as being lower” on the evolutionary tree.

This echoes ancient concepts like the “scala naturae” or “great chain of being” that ranked species in moral hierarchies—ideas largely rejected in Western thought but still present in other philosophical traditions. Some sub-Saharan African environmental frameworks, for instance, recognize a “hierarchy of existence” based on species’ different characteristics and purposes.

“These cases highlight the tension between the intrinsic value of a species and the benefits of eradicating a harmful pest,” explains Dr. Clare Palmer, a philosophy professor at Texas A&M University and study co-author. “While the suffering caused by these species is undeniable, the ethical implications of deliberately driving a species to extinction are profound.”

The Malaria Dilemma

Anopheles gambiae mosquitoes present an even starker moral calculus. These insects vector malaria parasites that kill over 400,000 people annually, with nearly 290 million infections worldwide. Gene drives could theoretically crash mosquito populations by skewing sex ratios, but the study argues this extreme step isn’t necessary.

The real target should be the malaria parasite itself, not its carrier. Eliminating Plasmodium—the organism that actually causes disease—could be achieved through modified mosquitoes that can’t transmit the parasite, combined with vaccines, bed nets, and improved healthcare infrastructure.

When Invasion Justifies Elimination

Invasive species on islands present the clearest ethical case for genetic eradication. House mice, black rats, and Norway rats threaten numerous endemic bird species with extinction on islands across Oceania. These rodents quite literally eat seabirds alive, driving vulnerable populations toward oblivion.

Gene drives targeting these invasive mammals would be more humane and environmentally targeted than current methods using traps and poisons. However, researchers emphasize that such approaches would only be acceptable for local extinction with virtually zero risk of global species elimination.

Setting Ethical Boundaries

The study establishes several criteria that must align before considering species eradication through genetic modification:

• The species causes extreme, otherwise preventable suffering to humans or animals
• Traditional control methods prove inadequate or impossible
• The species lacks critical ecological importance
• Risk of unintended consequences remains negligible
• Local communities and stakeholders participate meaningfully in decision-making

“Together, we argue, these cases suggest that deliberate full extinction might occasionally be acceptable, but only extremely rarely,” the research team concludes.

The Democracy of Destruction

Perhaps most critically, the study emphasizes that such momentous decisions cannot be made by scientists alone. Local communities—particularly Indigenous peoples with distinct land rights—must have primary authority over releases in their territories.

This creates complex governance challenges. Should global opinion matter when considering full extinction of a species? What about when technologies developed in the Global North target species primarily affecting the Global South?

“Our goal is to foster a more nuanced understanding of the ethical dimensions of genome modification,” Palmer notes. “We need to balance the potential benefits with the moral responsibilities we have towards all species.”

As genetic tools become more powerful and precise, these philosophical questions will only grow more pressing. The technology to deliberately extinct species already exists. Now comes the harder task of deciding whether we should ever use it.