
Self-Driving Genes Are Coming - bshanks
https://edge.org/response-detail/26769
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csense
Could this cause an apocalyptic worldwide famine if applied to plants that
form large parts of human food supply (e.g. by terrorists, rogue states, or as
part of the "destruction" phase of a mutually assured destruction)?

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robgibbons
Probably not much more than current crop seeds do, insofar as large volumes of
crops are already highly homogenous GMO breeds. I think this technique will
probably just be a better mousetrap for GMO breeding.

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Rhapso
I guess the question is: How do we target them? We don't really think about it
much, but there are a lot of methods of horizontal gene transfer even for
larger animals (viruses, inter-"species" breeding). How do we make sure these
extra potent genes stay in the intended organisms lines?

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jessaustin
Is CRISPR-driven homozygosity more likely to transfer between species than any
other? I suspect not. Would it be a problem if several different quasi-species
of mosquito lost the potential to incubate malaria? Again, no.

The thing to remember is that wild populations are still subject to selective
pressure, even with "driven" genes. If a gene is introduced that makes an
individual incapable of reproduction, that will have no long-term effect. Even
if the handicapped genetics can be spread widely through the population, it
will disappear within a generation, while non-handicapped genetics will
thrive. The trick will be to introduce changes that are benign enough in
survival terms to make it to the point of fertilization. At that point the
driven homozygosity will pitch in.

One could imagine a change that was subtle enough to survive but severe enough
that a population could get pushed out of its ecological niche. That's a good
reason to try this on pests rather than e.g. endangered megafauna, at least
until the consequences are better understood.

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sandworm101
> Would it be a problem if several different quasi-species of mosquito lost
> the potential to incubate malaria?

Yes. There is a reasonable chance that may go very badly. Malaria exists
within a very specific niche inside the mosquito. It has risen to the top of
the pyramid to establish dominance there. Knocking it from the pyramid,
removing malaria from the environment that is the inside of the mosquito, will
create a vacuum. Some other disease will rise to occupy the niche. Perhaps it
will be harmless, or perhaps it will be worse. But what is true is that
whenever a species is artificially removed another rises to take its place.

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jessaustin
Do plasmodia compete with each other for insect hosts? Is there some other
plasmodium waiting in the wings to wreak deadly havoc, if only it were free
from its nemeses _P. falciparum_ , _P. vivax_ , _P. ovale_ , _P. malariae_ ,
and _P. knowlesi_? This seems far-fetched, and besides why wouldn't the
genetic changes that make mosquitoes unsuitable hosts for the malaria we've
had for millennia also make them unsuitable hosts for this new malaria that's
going to evolve overnight?

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sandworm101
It isn't about only the plasmodia. Insects, all animals, have a an acceptable
parasite load. Too many and the host dies. Wild animals live pretty close to
that limit. So even if there isn't an exact swap-in replacement, by
eliminating malaria some other parasite will step up.

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jessaustin
It's possible to extrapolate too much from general biological trends.
Considering that the hypothetical "new" protozoan is as likely to target
black-bellied bustards as it is to target humans, and that malaria is an awful
blight upon humanity, I expect most humans would be pleased to make the
exchange.

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pcl
This article is a decent intro to the concepts and implications of gene
drivers. Based on the title, I expected something new; I thought "self-driving
genes" would be somehow different than the CRISPR-based developments of late.

