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Mosquitoes Genetically Modified To Crash Species That Spreads Malaria (npr.org)
An anonymous reader quotes a report from NPR: For the first time, scientists have demonstrated that a controversial new kind of genetic engineering can rapidly spread a self-destructive genetic modification through a complex species. The scientists used the revolutionary gene-editing tool known as CRISPR to engineer mosquitoes with a "gene drive," which rapidly transmitted a sterilizing mutation through other members of the mosquito's species. After mosquitoes carrying the mutation were released into cages filled with unmodified mosquitoes in a high-security basement laboratory in London, virtually all of the insects were wiped out, according to a report in Nature Biotechnology. The mosquitoes were created in the hopes of using them as a potent new weapon in the long, frustrating fight against malaria. Malaria remains one of the world's deadliest diseases, killing more than 400,000 people every year, mostly children younger than 5 years old. What's encouraging is that the mosquitos reportedly did not appear to further mutate in a way that would diminish the effectiveness of the engineered mutation. "But the researchers stressed that many years of additional research are needed to further test the safety and effectiveness of the approach before anyone attempts to release these mosquitos or any other organisms created this way into the wild," reports NPR.
That is of course something to be very careful about.
Because it is, multiple teams have studied the issue thoroughly and there seems to be broad agreement that eliminating the specific species responsible for most malaria would have very little ecological impact at all. There are plenty of other mosquito species (and other insects) to fill the niche. There are over 3,000 species of mosquito, only three (0.1%) cause most disease.
A key there is something like chemical pesticides wouldn't typically target just the species. Hence the search for a very targetted approach.
Well, no, it's a perfectly sensible thing to worry about. For example in Communist China, Mao encouraged everyone to wipe out sparrows because sparrows are a filthy nuisance and they eat crop seeds. So they did that, a government-driven program to eliminate sparrows. Yay, no more sparrows mucking the place up. Except, it turned out that sparrow ate a lot more insects than they did seeds, and after that China started to be beset with locust plagues which actually did wreck agriculture and millions starved to death. They then had to go over to Russia and buy sparrows to breed up and release in China to replace them.
Food chains are in fact pretty delicate things.
Baby dragonflies feast almost exclusively on baby mosquitoes. If you kill all the mosquitoes you will likely kill all the dragonflies. Adult dragonflies are an apex predator in the insect world and there are likely a lot of bugs that dragonflies eat that we wouldn't want more of.
Not almost exclusively. It is certainly a portion of their diet (as it is for many species). They get more nutrition from tadpoles, cadis fly larvae, baby fish, daphnia, ostropods, planaria, snails, and all sorts of other micro fauna. Mosquito larvae is just a part of their diet. They're also not particular about the species of mosquito. Only a small percentage of mosquito species bite people. You could wipe out the dangerous mosquitos and leave "human-friendly" ones alone- so their larvae and adults alike can be consumed.
"That's the way to do it" - Punch
The screwfly solution exploits a rather unique quirk of the screwfly itself. The females are only able to mate once. If a sterile male reaches a given female first, boom, no fertilized eggs from that female. If you release a large enough number of sterile males into an area they win the race to the females most of the time by sheer numbers and the population crashes in short order. After a few cycles of this total eradication is easily achieved. With most other insect species if a sterile male mates with a female a naturally occurring fertile male can come along 5 minutes later and ruin the whole plan.
We're going to make information free Mr. Anderson, whether you like it, or not.