Should we commit mosquito genocide?

Getty Images/nechaev-kon

Peter Franklin

September 28, 2018 3 mins

It’s something you may have seen at the zoo. A sign that reads: “The most dangerous animal on Earth!” Next to it, of course, is a mirror.

But is it true? Are we really our own worst enemy? Probably not. Unless there’s a world war on, the animal that kills the most people each year is the mosquito.

In a piece for Quillette, James D Miller lays out the charges:

“Mosquitoes kill around 830,000 people each year mostly by spreading malaria in underdeveloped nations. Mosquitoes sicken and cause lifelong debilitation in many who don’t die. By decimating human capital, mosquitoes do much to keep poor people poor.”

If that weren’t enough he adds this cheery thought:

“With their ready access to our blood, mosquitoes may even give future bio-terrorists an easy attack vector.”

But what if we do for them before they do for us? As I’ve written about before, gene drive technology provides us with a possible means of deliberately targeting an entire species for extinction.

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Do we have the right? Yes, says Miller – indeed, it is our duty:

“To eliminate this menace, we need only exterminate the 100 of the 3,500 or so species of mosquitoes that bite humans. Given that we very likely have the technology to eliminate human-biting mosquitoes at a relatively low cost, not doing so is Hitler-level evil. If a new dictator arose and started killing 830,000 people a year, we would all accept the moral value of stopping him. “

No pressure, then!

Miller does admit there may be ecological side effects. These are the subject of an article for the Atlantic by Sarah Zhang:

“To humans, mosquitoes are at best annoying and at worst deadly, but to dozens of other species in the wild, they are competitor, pollinator, or prey. If past malaria-eradication campaigns have taught us anything (see: 1950s, DDT), it is that reshaping the environment can have unintended consequences.”

So what would happen if we were to permanently swat an entire mosquito species? Target Malaria — “a Bill Gates–backed nonprofit research consortium” – is trying to find out:

“In October, a team of Target Malaria scientists from the University of Ghana and the University of Oxford will embark on a four-year study of the ecology of the malaria mosquito Anopheles gambiae in Ghana. Ultimately, they hope to understand how fish, bats, flowers, and insects would respond if those mosquito populations were reduced—or even entirely eliminated.”

Worthwhile research, I’m sure. But I wonder if, once again, technology is developing faster than our ability to fully understand its implications. In four years time, another group of researchers might have a gene drive weapon ready for deployment.

Miller makes the very strong point that it would take a awful lot of unforeseen ecological damage to outweigh the benefit of saving of 830,000 human lives each and every year.

The mistake, however is to look at each gene drive weapon in isolation (or even the multiple gene drives that would be required to wipe out the 70 (out of 3,000) mosquito species that can transmit malaria).

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Any individual gene drive – indeed any environmentally released genetic modification of any kind – advances our knowledge of how to make other gene drives and modifications. Thus every advance is one step closer to the step too far: to the genetic manipulation that brings about disaster.

To some extent the same can be said of all technologies. For instance, research on a robot designed to help the disabled potentially contributes to the development of robots designed to kill people.

The special problem with genetic modification, however, is its irreversibility. Once out in the environment it literally has a life of its own. Unlike all other classes of technology it can reproduce and mutate without any further assistance from ourselves (though the same may become true of artificial intelligence).

In the case of a gene drive, the modification is designed to propagate itself through the target population – and if, by some genetic misadventure, it should jump across the species barrier into another population it will continue to propagate. Indeed, when the modification is designed to drive whole populations extinct, the gene drive modifications that persist out in the wild will, by definition, be those that have either failed in their intended purpose or which have an unintended propensity to jump from one population to another.

It’s called survival of the fittest or, in the latter case, the deadliest.