Eradicate mosquitoes

Graphic by Jian Bautista
Graphic by Jian Bautista

Most Alaskans can pass mosquitoes off as an annoyance. Little things hell-bent on infiltrating your tent, buzzing in your ear and leaving you with an itchy bite. But in other parts of the world, mosquitoes are the harbingers of misery and death. Upwards of 725,000 humans per year are killed by the diseases that mosquitoes spread, earning them the heinous title of the “world’s deadliest animal.” Malaria, Zika, West Nile, dengue, chikungunya and yellow fever are just some of the many awful diseases transmitted by this vector organism.

Endeavors to control this ruinous insect tend to be short-term. Nets can be draped over windows and doors. The ponds in which they reproduce can be drained or fogged with pesticide. Species like fish and fungi can be introduced to prey on larvae. But mosquito populations eventually rebound, and time is running out. Global warming is likely to create more warm and wet environments that mosquitoes thrive in.

We possess the means to fix this once and for all. A permanent solution to make our world a safer place. A massive, concerted effort to achieve one goal: the eradication of the mosquito. It is time to engineer an extinction.

Such a project should not be conducted with whimsy. Humans have a long history of forcing other species into extinction, but such outcomes were often unintended and brought shame upon our reputation. Mosquitoes are another matter entirely. Intentionally destroying an animal that has remained competitive for at least 46 million years raises serious ethical concerns. But failing to prevent mass death when we have the means to is worse.

Let us start with honing in on our target. There are more than 3,000 species of mosquito in the world. The Aedes aegypti and Aedes albopictus are the two that should earn our wrath first since they are the most common vectors of disease. Targeting them will require a massive international campaign similar to the World Health Organization’s successful eradication of smallpox by 1980.

Next, we need to consider the tools to accomplish this. Above all, we have to be smart about it. Mosquito eradication efforts in the 20th century yielded unacceptable environmental damages that we should obviously not repeat. So that rules out intentionally filling waterways with oil, as the Americans did while building the Panama Canal. Nor should we expand chemical operations including pesticide and the repellent DEET, given the evidence of environmental and health concerns related to those tools.

The smart option is through genetic engineering. The gene-editing technique CRISPR allows scientists to edit the DNA of an organism. Most of the research on this technology has been in the pursuit of removing genes, particularly harmful ones that make an organism more vulnerable to disease. For mosquito annihilation, however, we will need to employ the inverse of that. Insert a gene into mosquito DNA that gives the species a disadvantage in natural selection.

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The sabotage gene would need to be patient. It cannot be too lethal, because the first batch of lab-grown GMO mosquitos will need to reproduce with wild mosquitoes enough to spread the gene. Under normal conditions, the sabotage gene would only have a 50 percent chance of being passed to offspring. That is not enough. Thankfully, the gene drive technique allows scientists to increase the probability that the desired gene will be passed on. For example, every mosquito inherits chromosomes equally from two parents. So they have a 50 percent probability of inheriting our sabotage gene. But if we can design that gene to convert the other chromosome that it is paired with, then the GMO mosquito has duplicate corrupted chromosomes and a higher chance of passing the sabotage gene on to its offspring.

So what does our ticking time bomb gene do? It renders the female mosquito sterile. The gene must not affect the male mosquitoes, because we need them to continue mating and passing on the gene. So the first release of these GMO mosquitoes must all be males. This first generation will mate entirely with wild females, resulting in a second generation of fertile males and sterile females. Half of these second generation males will end up with sterile females, and the other half will succeed with wild females. Given that mosquitoes have short lifespans and speedy reproduction, our sterility gene will be endemic in their species within a few generations.

Eradicating mosquitoes with this technology needs to be done right. If it goes awry, then the backlash will be so severe that scientists won’t be able to try again for quite some time. So the World Health Organization will need to work closely with partners to securely deploy these GMO mosquitoes in phases. The first phase is releasing them in controlled environments with wild mosquitoes to measure how long it takes to obtain 100 percent sterility. The second phase is through facilities in select disease-prone countries, so that the sabotage gene can be tested in diverse ecosystems. The final phase is a full release in the wild.

Wiping out mosquitoes will affect the ecosystem, but to what extent is debated. It is true that these bugs are a food source for some animals. But the preponderance of evidence indicates that a mosquito apocalypse will not be mourned very much. They play a minuscule role in predator’s diets compared to larger and more nutritious alternatives like moths. Plus, the fact that multiple children have died from malaria since you started reading this article is enough to override most other concerns. Let us put a stop to that misery by taking a hard look at the animal that spreads it.