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Comment by mbeavitt

7 hours ago

Oh come on. Does anyone actually believe gene drives will work? This fundamentally goes against the principles of natural selection.

A gene which incurs a fitness cost will be purged from the population under selection!!

Aedes aegypti are container breeders, you can totally eliminate them from an environment through diligent removal of standing water left in buckets, tires, pots, etc. This has been done before but the effort wasn't properly sustained so they've made a major comeback in disease prone areas. Killing a lot of them does have a substantial effect because they don't easily travel long distances by themselves so if the remaining resistant population is small enough it might just as easily end up dying out due to its breeding cycle being interrupted through other means. The part that should be criticized here is that any eradication campaign should also involve efforts to eliminate their breeding environments by removing junk and unattended containers that collect water.

Sterile insect releases are a tool for suppressing populations and have been used for about a century. This is not really a new suppression technique but a novel way of producing the sterile insects.

It has been used to suppress screw worm in the United States for decades until the administration cut the funding.

These are almost always a temporary solution that need constant funding and seasonal releases to work. The populations will surge back as soon as it's stopped.

The idea is to hit the population with a cataclysm so sudden that it goes extinct before it can adapt. We can calculate mutation rates and reproduction dynamics, so we know how to predict whether this is likely or not.

If it's one-and-done, everywhere on Earth (eg smallpox), it can work. If it drags on for decades or isn't rolled out globally (eg malaria) then it won't work.

>Sustained releases cut a wild Aedes aegypti population in the Cayman Islands by 80 percent, and in a field trial in Juazeiro, Brazil by about 95 percent.

  • Female mosquitos mate once and only once. When they mate with a sterile male, none of her eggs will hatch.

    Several insects are like this. In the species I'm familiar with, the male member breaks off inside the female locking all other males out.

    Releasing sterile screwworms in Panama has been the main method of protecting US beef/cattle production from the insects spreading north out of South America.

    https://www.pbs.org/newshour/nation/what-to-know-about-the-n...

  • Penicillin used to kill 100% of Staphylococcus aureus. My point still stands - even if a selective sweep takes out 99% of the population, they will recover.

    This is at best a temporary solution.

  • The remaining 5% and their adapted mutation will eventually repopulate the local population.

The gene gives a sizable advantage to mosquitoes that don't carry disease. Those mosquitoes will then take over the niche making it very difficult for disease carrying mosquitoes to come back.

I think you’re right. I’d want to pair this approach with introducing a replacement species that can hopefully out compete the one we’re eliminating. No idea what that looks like, though.

That may very well mean the eradication of the population. Also we can do the gene drive repeatedly reintroducing the gene. Or modified genes.

Depends how fast the gene drive works. Natural Selection is slow.