
New Model Warns About Crispr Gene Drives in the Wild - sampo
https://www.quantamagazine.org/new-model-warns-about-crispr-gene-drives-in-the-wild-20171116/
======
SteveGregory
Gene drive is a very scary thing from a strict biological standpoint. Just
imagine a gene that must be passed on to _all_ offspring, rather than randomly
chosen. We could quite easily wipe out entire biomes with such a technology.

This should not be underestimated, or thought to be less relevant of a weapon
than, say, the atomic bomb. It's just slightly more subtle than explosives.

Yes, there may be benefits if used well. And yes, nuclear technology can be
(very) useful for generating power. I'm just saying that there needs to be
more attention here. The particular uses need to be more widely understood and
talked about.

~~~
maxerickson
It's a common breeding technique to create individuals with identical gene
pairs so that all offspring will be guaranteed to have the gene. This is what
"purebred" means.

[https://en.wikipedia.org/wiki/True-
breeding_organism](https://en.wikipedia.org/wiki/True-breeding_organism)

~~~
Obi_Juan_Kenobi
Not the same at all.

An individual homozygous at a given loci has no guarantee that its offspring
will also be homozygous. It will have one copy from that parent, but the other
parent may or may not provide an identical copy. If it's a new trait (say a
doomsday gene), then no other copies exist in the breeding population, and all
offspring will be heterozygous. If the overall population is static, then
average expected fitness is two offspring that make it to breeding. Thus,
there will be two copies of the 'doomsday' allele in the population, just as
there were in the original homozygous parent. In other words, the total number
of alleles remains static over time.

In order for an allele to take over a population (become fixed), it must
confer a fitness advantage, or else make it there by pure chance. Relying on
chance, you have to introduce huge amounts into the population so it becomes
the majority, otherwise it will be eliminated.

Gene drive is completely different as these constructs can copy themselves to
the homologous chromosome in heterozygous individuals. Offspring will be
homozygous even when only one parent contributes the allele, and thus the
expected allele content in the population will double each generation. Now
only a few individuals need to be introduced into a population for the trait
to become reliably fixed.

It's exponential, and it's truly terrifying.

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patcheudor
John Sotos, Chief Medical Officer of Intel covered the dangers of this
technology quite well at DEF CON 25. If you've not seen his talk, watch it
now, it's in my top ten of the best talks I've been to in the eleven years
I've been going to DEF CON:

[https://www.youtube.com/watch?v=HKQDSgBHPfY](https://www.youtube.com/watch?v=HKQDSgBHPfY)

~~~
llamataboot
Well, that gave my dystopian dreams new levels of dystopia that I didn't even
know could exist.

~~~
FabHK
Starting with the fact that Intel has a Chief Medical Officer.

~~~
lobotryas
Why is that surprising or disturbing? IBM has long ago moved towards becoming
a service company and if they want a large slice of the Healthcare industry
pie then they'll have someone focused specifically on that.

~~~
beojan
This is _Intel_ , not IBM.

------
rdl
I have a secret plan of once I have >$10mm in free cash, doing gene drive
elimination of the disease vector mosquitoes without getting any permission or
notification by any states. I’m not sure if someone else will beat me to it,
but I’d be perfectly happy to stand before the UN or whatever after having
done it.

~~~
tomaskafka
Read this story first, please: [https://www.quora.com/If-mosquitoes-were-in-
danger-of-extinc...](https://www.quora.com/If-mosquitoes-were-in-danger-of-
extinction-would-we-try-to-protect-them-or-try-to-get-them-extinct/answer/Jay-
Bazzinotti)

> Within a month we destroyed the mosquito population. We could actually go
> outside in short sleeves again. We were very, very happy.

> It didn’t take long to notice the change in the ecology, however. Being in a
> rural area we had a large amount of diverse animals and birds. When the
> mosquitoes went, all the birds went too. Not a few birds, not just the song
> birds, but all the birds. We created our own “silent spring”. The bats and
> dragonflies also went away and with them many of the fish in the lake became
> more voracious and desperate to eat, which meant that they were much easier
> to catch. In a short time the lake was fished out. And because all the birds
> were gone we got a tick explosion. Instead of mosquitoes we now have ticks
> everywhere. It’s annoying to be constantly pulling off ticks, checking for
> ticks and finding ticks attached to one’s genitals. In addition, there have
> been a number of cases of Lyme disease as a result.

...

> The Law of Unintended Consequences is a very powerful law. You may be
> attempting to do something good over here but the result is an unforeseen
> and negative change in the infrastructure over there. It’s funny now how we
> get together outside and notice how dead we’ve made the area by killing all
> the mosquitoes. It looks beautiful, just like the environment looks OK in
> Rachel Carson’s “Silent Spring”, beautiful to look at, but devoid of life,
> devoid of sound and requiring constant laundry, showering and tick checks.
> It’s extremely disheartening to come into the house and finding a tick
> attached to your genitals. And although we cannot attribute it to our
> killing of the mosquitoes, the leech population has exploded in the lake as
> well. Maybe the loss of all the fish that ate the mosquitoes and leeches
> allowed the explosion of the leech population.

~~~
osteele
This is a fun and well-told anecdote. Maybe correlation in this case was
indeed causation. But…

There's less consensus among scientists than there is on Quora. A few
interviews and quotes:

* “Ecology: A world without mosquitoes”, Janet Fang, Nature, 21 July 2010. [https://www.nature.com/news/2010/100721/full/466432a.html](https://www.nature.com/news/2010/100721/full/466432a.html)

* “Zika Raises the Question: Are Mosquitoes Necessary?”, Jason Bittel, National Geographic, February 7, 2016. [https://news.nationalgeographic.com/2016/02/160207-mosquitoe...](https://news.nationalgeographic.com/2016/02/160207-mosquitoes-zika-virus-environment-science-animals/)

* “What If Every Mosquito On Earth Went Extinct Tomorrow?”, Ria Misra, October 15, 2017. [https://news.nationalgeographic.com/2016/02/160207-mosquitoe...](https://news.nationalgeographic.com/2016/02/160207-mosquitoes-zika-virus-environment-science-animals/)

I'll tentatively add that this topic came up at a dinner with Pardis Sabetti
[https://www.sabetilab.org](https://www.sabetilab.org) and George Church
[http://arep.med.harvard.edu/gmc/](http://arep.med.harvard.edu/gmc/). At the
time, neither of them thought mosquitos were an essential part of any animal's
food chain. Except that I'm not 100% sure we were talking about mosquitoes at
the time – maybe we were talking about some species of bats. :-(

[By the way, Grayson Brown's quote “the ecological damage […] would make
eradication not worth it unless there was a very serious public health
emergency” may sound clueless or heartless. Charitably, maybe he was referring
to eradication in developed nations only, and maybe the full interview – which
I haven't listened to – makes this clear.]

~~~
rdl
This debate is exactly why I think some individual or small group is just
going to do it without asking permission.

------
samirillian
Is anybody going to mention the elephant in the room here? Viz., We are all
discussing a legitimately framed wariness/fear of GMOs. Correct me if I'm
wrong.

~~~
thriftwy
Currently, when non-modified crops have offspring with GMOs, the result is
usually unviable (because that's what GMO owners would like) or distributed
accordingly to Mendel laws. If modification is maladaptive, it's going to
disappear. If it's cosmetic, it's probably not going to dominate.

But with gene drive, virtually every offspring will be modified to, and their
offspring too, leading to modification of the whole species to monoculture
gene.

------
m_mueller
I'm just imagining a terrible racist dystopia where totalitarian fascist
regimes use gene drives and co. to weaponize the DNA of their population.
Imagine the social effects of people who look a certain way having genes that
make it such that their babies will inherit certain traits with 100% chance.
You'd end up with _actual_ race wars. Children would be raised to avoid
interacting with other races. _shudder_

~~~
jessriedel
It would take hundreds or thousands of years to play out. Not a very effective
strategy for a despot.

~~~
Xeoncross
Genetics have already played out enough for people to kill based on them. Look
at Hitler. Look at African civil wars. Look at the riots/revolutions against
"foreigners" in Asia.

~~~
ejstronge
I'm confused about your African civil wars comment - what were you referring
to?

~~~
richardknop
Several genocides happened in Africa so he could be referring to one of them
(Rwanda genocide as mentioned next to this comment is well known, recent
genocide in CAR and so on) or all of them in general. Most western people are
mainly familiar with Holocaust as the big example of genocide but there have
been several comparable horrific events across continents (Africa, Asia and I
think also South America).

------
chiefalchemist
Mother Nature is a complex system. Grab the balloon at one end and it pops out
in some other unintended place. Perhaps it's time we fix the gene that
prevents us from recognizing this?

~~~
Arbalest
I think this is already well understood. The problem is, there's nothing we
can do to determine what this place is. The alternative is to change nothing
and stop progress. If we end up killing ourselves as a species, so be it.

I would suggest this is different from denialists in the case of climate
change however. Being faced with evidence is different from being faced with
the unknown.

~~~
goatlover
Or you know, be the slightest bit cautious instead of plunging ahead with
doing things like building nuclear arsenals.

------
mrfusion
I don't understand why this never evolved naturally with selfish genes and
viruses and all. Anyone know? Perhaps cells already have a built in defense
for this kind of thing?

~~~
HarryHirsch
Look up P-elements in Drosophila. It's the stuff of nightmares.

~~~
toomanybeersies
I googled them, but as I was reading about them, I realised that I skipped
high school biology.

Care to give a laymans' explanation?

~~~
ethbro
Don't worry, that's definitely above high school biology level. Here's the
most readable article I could find:

[https://www.ncbi.nlm.nih.gov/books/NBK21254/](https://www.ncbi.nlm.nih.gov/books/NBK21254/)

In summary (me: CS background, biology family), there are self-mobile genetic
sequences (in that they themselves encode the molecular machinery necessary to
move their string of DNA to a different location in the genome) in some fruit
fly populations.

Additionally, the implementation of this also gives rise to a phenomenon
called _hybrid dysgenesis_ whereby the sexed cross of one type (female
without, male with) causes rampant mutations in offspring. Whereas the
oppositely sexed cross (female with, male without) has much of the P activity
suppressed and therefore able to live.

Presumably this terrifies parent poster because one could hypothetically
create a situation where only a population with the genetic secret contained
in their females would be able to successfully reproduce.

------
RRWagner
It's difficult to think of any new and powerful technology (radio,
electronics, computers, programming, viruses, even nuclear reactions) that
didn't eventually become available to a teenager in their basement. The most
likely end-of-world-as-we-know-it scenario is when used or home-built Crispr
tech is in the hands of adolescents who think it will be fun to create a real
fatal, rapidly spreading human virus, or wipe out species x, etc.

------
Arbalest
Perhaps cheaper and more widespread gene sequencing should be considered
before pursuing something which could affect entire populations of X species.
I can imagine something like this wiping out some kind of pollinating insect,
for example. Any such population would have to be monitored regardless of
local isolation by design. For that we need very cheap sequencing.

------
erikpukinskis
I keep wondering: what actually is between us and a Handmaids Tale-style mass
sterilization event? If someone releases a global flu virus that also causes
us to bear infertile children, what would protect us?

Is it just that someone would probably notice and we could inject our kids
with refertilizing viruses?

How does that arms race play out?

~~~
ben_w
> If someone releases a global flu virus that also causes us to bear infertile
> children, what would protect us?

I think it’s now possible to convert any human cell into a stem cell, so we
would probably make that tech cheap enough to widely deploy and then — given
human nature — let poor people die childless.

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epmaybe
I may be wrong, but this is only if you use CRISPR for modifying embryonic
genes, right? If you induce somatic mutations/insertions/deletions, this
wouldn't have the same effect of passing it down to offspring? Perhaps that's
not an ideal solution for all genetic diseases, though.

------
bluGill
But of course they have concluded that random mutations won't result in the
same.

In fact they have not. We need to be careful of course, but Crispr when you
are careful is less risky than just hoping that the next random mutation is
good.

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RcouF1uZ4gsC
Based on this article, it seems that the model would say that we could use
CRISPR to wipe out disease carrying mosquitoes even in the face of
evolutionary adaptations. This would seem to be a good thing.

~~~
tomaskafka
Law of unintended consequences:
[https://news.ycombinator.com/item?id=15931659](https://news.ycombinator.com/item?id=15931659)

~~~
thriftwy
> I’m not going to kid you. It’s excellent now that the mosquitoes are gone.
> We don’t regret making that big effort.

From the post you are quoting. Sounds like a success story with a few
drawbacks.

------
wyldfire
Pigoons and rakunks here we come.

~~~
tim333
Had to google that. For the benefit of others:

"In Margaret Atwood's Flood Trilogy — a speculative fiction series about
scientific advancement spiraling out of control and ending civilization —
genetically engineered pigs called "pigoons" roam a post-apocalyptic Earth. "

