As gene drive modifications become more accessible, preventing this becomes impossible.
The ones that carry malaria will almost certainly be wiped out.
https://www.npr.org/sections/goatsandsoda/2021/07/28/1020932...
"genetically altered mosquitoes to block the activity of a specific olfactory receptor called Ir8a. The result was that female mosquitoes — which are the ones that suck blood — were no longer attracted to lactic acid, an important component of human sweat."
So if we could refine this just a little bit more, we could engineer mosquitos which don't bite humans. And put that into a gene drive.
Still scary as fuck to mess this deeply with nature (note: post-doc work on viral evolution), but this is a less severe change than sterility.
This is always discussed in terms of the mosquitos and the population(s) of mosquitos.
Should we think, at all, of the population of malaria, globally ?
Is it possible that we could exert this tremendous pressure - an evolutionary chokepoint - on malaria and it escapes in some unexpected manner ?
This is not an area I have any background in so I hope someone can comment on this idea:
If we back an organism like malaria in a corner might heretofore out-competed mutations ascend and suddenly malaria comes at us from a new direction ?
The vast majority of non-bacterial species that are subjected to severe evolutionary pressure go extinct. The main reason this happens is they cannot adapt rapidly enough to respond to evolutionary pressure.
Malaria is a very complex parasitic disease which depends on a whole series of things going right across multiple hosts. If it's disrupted in either the mammal host or the insect host it's unable to reproduce. There's a number of disruptive events that can happen (such as blood cells being the wrong shape, preventing infection from the parasite). There's no variants of malaria that can infect sickle-shaped blood cells even though sickle-cell anemia is very common in malaria regions.
Unlike viruses and bacteria, there's no easy mechanism for a new variant of a parasite to spread its mutation laterally. The replication mechanism for parasites occurs much less frequently and produces much fewer copies than bacteria or viruses do. RNA-based viruses have very high mutation rates in general, due to the defects in RNA replication. The viral life cycle happens anew with every cell infection. Bacteria are even more adaptive - they can actually exchange genetic material even between replications, and of course replicate exponentially without depending on host cells. This is why viruses and especially bacteria can rapidly respond to evolutionary pressure. Other species are not so lucky. For a malaria parasite to respond to evolutionary pressure, it would have to go through its entire multi-host song and dance on every replication cycle. This already massively slows down mutations, as the number of mutations depends on the number of replications and the probability of mistranscription in each replication. But the important thing is that we are already using heavy interventions to prevent the spread of malaria - if we can drop the base rate of spread by some tens of percent and keep those measures, malaria will go extinct. If we remove the index host species (the particular susceptible mosquitoes) it's going to take a very long time for the parasite to successfully infect another species, as the number of replications drops massively and there's no replication reservoir where a new variant can develop. As the individual parasite's lifecycle is short, extinction is much more likely than adaptation.
I was not aware until just now that malaria is neither virus nor bacterium.
Thanks - appreciate your response.
I honestly don't know: will this affect the ecosystems? I think (at least) dragonflies eat mosquitoes. No idea how much the depend on them for food.
One mention of "gene" and you attract all the conspiracy theory evolution deniers that suspect the upcoming zombie apocalypse behind the most mundane technology, all the while combusted dinosaurs takes them to their job.
Don't worry, "the ecosystems" are perfectly fine with things appearing and disappearing constantly for the most random reasons.
What happened to "the ecosystems" when we went from millions of humans to billions is the extinction of many species, and disappearance of biodiversity in general :
> In absolute terms, the planet has lost 58% of its biodiversity since 1970 according to a 2016 study by the World Wildlife Fund. [0]
The ecosystems are definitely not 'perfectly fine' if we keep messing with them [1]
If you want something less dry than pure numbers, you can check the docuserie "Our Planet" on Netflix
[0] https://en.wikipedia.org/wiki/Biodiversity#Threats [1]https://www.science.org/lookup/doi/10.1126/science.345.6195....
Well, its called "the sixth mass extinction", so I'd guess it isn't good.