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Comment by netgusto | Hacker News Reader

Maybe an irrational fear, but how can we be absolutely sure (as in total certainty) that this kind of manipulation cannot "jump" to another living thing? Through mosquito bites, or by the mosquitoes being eaten by other animals, or perhaps by another, more subtle way?

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Have already commented elsewhere, but keep in mind that any gene mutation that we try to enforce is already likely to have happened billions of times (DNA changes at every instance of sexual reproduction, that's why we're not clones of our parents, that's step 1 of evolution as well). If DNA changes in parasites affect hosts, then this is already going to be happening for all kinds of weird changes.

As the article explains fairly well, this technique targets a gene that, if it mutates, causes that mosquito to be sterile. So when it happens de novo, you have a sterile mosquito that is simply not going to pass its genes along. Since this technique leaves the male mosquitos alone, it will spread as they mate with unaffected females (spread as in being transmitted to offspring — it’s not a virus, etc).

It is not the case that because all possible mutations have and will continue to occur, all mutations are safe to be technologically propagated. There are many discovered and as yet undiscovered mechanics and ecologies involved in which mutations can propagate naturally.

Sulams reply has the real main reason for confidence in the safety of propagating this mutation.

Doesn't it happen already? Half of human dna is old viral load. Perhaps a mosquito virus will take on this gene drive, arrive in humans through a mosquito bite, spread it from there.

This is not a mutation. It's an engineered change equivalent to many many mutations - probably thousands at once. The probability that this would randomly occur in nature is essentially zero.

While I agree I feel compelled to mention survivor bias. If this had happened before to a species it is unlikely you'd know since they'd all be dead.

This one couldn't jump outside insects, perhaps specifically flies, it targets a specific gene mosquitoes have in common with the well studied fly Drosophila.

Which would be bad enough. These gene drives are extinction weapons. If they get into something with a wide range and high importance to any given ecosystem, well, I hope you took wildlife documentaries of it while it was still there.

How can we be certain that any chemical we put into the environment will not cause some catastrophe? We can’t. We can only study the solution until we get to some reasonable level of certainty.

Manipulating genes is different, if the genetic variation can be transmitted somehow (as occurrs in GMOs, I gather) then the influence is transmitted. It's viral (no pun intended) and subject to random mutations that may be more virulent.

With chemicals they tend to degrade.

It's like the influence of single chain letter that's physically passed from hand to hand (and eventually falls apart) vs a Facebook post that's effectively infinitely duplicable.

The diligence in handling genetic solutions to biological problems needs to be substantially greater.

There are plenty of chemicals that don't degrade or degrade extremely slowly (e.g., PCBs, radioactive chemicals), and which can influence a species or ecosystem over many generations. Introducing genes definitely pose risks, but I they aren't fundamentally different from any other dangerous chemicals. We have tools and frameworks to evaluate this risk.

It is not the case that all types of chemical are equally mysterious to the environment. Fundamentally if the chemical or thing is already in the environment then we can quite confidently deduce the environment is evolved to work with not dissimilar amounts of it.

Because porting genetic modifications between species is really hard even if you intentionally try.

You need it to be impossible if you want to ensure you only eliminate species you're targeting instead of that species and random selection of others.

Life finds a way :-P

Ugh. You joke, but I loathe that sentence. Absolutely loathe it. The version in Crichton's book wasn't as bad as the tripe Ian Malcom spouted in the movie, but it's had a toxic influence on pop culture understandings of science and genetics.

More detail would be helpful. What was Chrichton's version? Why has this movie line been bad for popular understanding?

Are you having sex with mosquitos? No? Then you'll be fine.

As for any kind of bizarre viral-mediated horizontal gene transfer scenario, there's no more risk of this happening than for any other harmful bit of another species' genome. This is the kind of thing that can, in particular circumstances quite unlike these, occur over evolutionary time.

But on the face of it, it's absurd; there's tons of potentially harmful genetic material out there, just oodles of all manner of virus even, that can't infect humans for the simple reason that .. it can't. This isn't unknowable magic.

In the infinitely more likely scenario that gene drive is used maliciously, it would still be quite easy to do genetic screening, and thus fairly easy to avoid having compromised offspring.

The 'doomsday' scenario for gene drive is malicious use for ecological destruction.

I don’t believe this could be transmitted by a bite. I understand this also requires that the target which is jumped to has the mosquito gene being targeted. I think non-mosquitoes don’t have this gene. I think this technology also works better on things that don’t have many cells.

In the utterly unlikely circumstances given what we know then we could reverse it because we stumbled upon a holy grail of genetic engineering completely by accident - being able to propagate lasting changes that easily. In which case break out the champagne because we figured out how to propagate the cure for myraid genetic diseases by complete accident.

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