If we had the power to make mosquitoes go extinct, would that be a good idea? Scientists and policy-makers might be facing that conundrum sooner than you think.
It’s an idea that’s been kicking around for a few years now: given the devastating public health impact of mosquito-borne illnesses around the world, wouldn’t it be a good idea to eradicate them completely if we could?
Surprisingly, based on our present knowledge, making mosquitoes disappear from the face of the Earth forever would probably not lead to any crazy ecological downsides, with some possible short-term exceptions.
As far as we can tell, there would be no knock-on effects of other species going extinct as a result, or of some other species booming uncontrollably as a result, or any other of the usual madness you might expect when removing a giant Jenga block from a complex ecosystem.
But our knowledge of these things is incomplete at best. It seems like common sense to consider the possibility that there would be unforeseen, potentially devastating effects of such a bold move, which we might just not be able to predict:
Still, it’s easy enough for people in developed countries to err on the side of caution when it’s not our family members and friends who are dying of mosquito-borne illnesses at depressingly high rates.
It ends up being an ethical question: would it be morally defensible to not eradicate mosquitoes if we could, given the huge number of human lives that would be saved, and all the human suffering that would be prevented?
Well, hold on. That’s a big of a false dichotomy, as there are other possible options, such as just trying to eliminate the diseases themselves, or find better ways to prevent them, or find ways to alter mosquitoes in a way that would prevent their transmission, possibly by way of human-made modifications to the mosquito genome — although that last option carries the same old risk of unforeseen consequences.
And once the toothpaste is out of the tube, there’s no getting it back in.
Some of the possibilities of taking a gene-based approach to the problem could involve the much-touted CRISPR technique to introduce changes into mosquito DNA:
But what about just stopping the damn things from breeding so much?
The good (or bad?) news is: interfering with breeding success is actually being attempted on a smaller scale.
Most recently, it’s been happening right in Australia’s backyard, in the Pacific Islands.
Scientists in Tahiti, concerned about the spread of Zika in the Oceania region, have been introducing a bacteria called Wolbachia to mosquito populations on some of the islands in the French Polynesia region.
The bacteria is already found naturally in about 65 percent of mosquitoes globally, but it exists in many different strains. And here’s the thing: when mosquitoes carrying two different strains of Wolbachia end up mating, there are often problems with the resultant mosquito eggs — problems which can prevent them from hatching at all:
The idea is this: infect mosquitoes in the Pacific with a non-native strain of Wolbachia, and you’ll seriously shrink the size of the next generation as more and more mating pairs produce dud eggs due to the parents carrying different strains of the bacteria.
This actually isn’t the first time such a thing has been tried. Some islands in Guangzhou, China used the technique to nearly eliminate mosquitoes locally, and similar experiments have been carried out in small regions of the Americas, among other places — including Australia:
So will this ultimately lead to the extinction about which so many are uneasy? Not necessarily, but it could represent a major move in that direction as the Wolbachia-based approach becomes more popular.
With this most recent push in the Pacific regions, entire large islands could see their mosquito populations decline by 70 percent in the coming years.
Knowing humans, it’s only a matter of time before we go for the big roll of the dice, trying in earnest to eliminate most or all of the mosquitoes across large regions of the planet, and maybe eradicating them altogether soon enough.