Comment by reidacdc | Hacker News Reader

Comment by reidacdc | Hacker News Reader

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This raises a question for which I have never found a satisfactory answer, perhaps some of the people chiming in here can help.

It seems likely (intuitively, which is why this is a question) that a naturally-occurring mutation which is artificially selected-for by a grower actually is very different from a transgenic insertion. The former arises within the complex regulatory/inhibitory genetic environment of the natural plant, so it sort of feels less risky, less likely to be disruptive or to renovate the biochemistry. Transgenically-inserted genes are mitochondrial, activated by default, and not part of a regulatory chain, and may produce arbitrary metabolites -- this is where they get their power. An ecosystem analogy comes to mind, natural mutations are like species evolving in an ecosystem, and transgenic insertions are like invasive species, potentially throwing the ecosystem seriously out of whack.

Is this just a sort of romantic fallacy, supported by a bad analogy?

I think it's tangential to the safety question -- actually-existing commercial GMO crops have been tested and demonstrated to be safe, that seems to be clear. But I think the space for unsafe combinations is much larger than it is for natural mutations, and the analogy to selective breeding understates the danger (and the power)?

> a naturally-occurring mutation which is artificially selected-for by a grower

Actually plant breeders use radioactive radiation, and certain mutagenic poisons, to increase to mutation rate way above normal, in order to get more mutated offspring to work with.

What you write about "transgenically-inserted genes are mitochondrial" and "not part of a regulatory chain, and may produce arbitrary metabolites" is total bollocks and I have no idea where you got that particular misinformation from.

https://en.wikipedia.org/wiki/Mutation_breeding

A natural nutation may be dangerous. For example the difference between the sweet and bitter almonds is a single gen. https://en.wikipedia.org/wiki/Almond#Sweet_and_bitter_almond...

In particular:

> The acute oral lethal dose of cyanide for adult humans is reported to be 0.5–3.5 mg/kg (0.2–1.6 mg/lb) of body weight (approximately 50 bitter almonds), whereas for children, consuming 5–10 bitter almonds may be fatal.

The mutation that makes the bitter almonds produce cyanide is very old, totally natural and dangerous. It was mutated at least 300 million yeas ago, before the almond became a different plant than peach and cherry and other similar plants. Probably to make the animals avoid the plant and kernels.

> It was mutated at least 300 million yeas ago

I don't know, the whole group of flowering plants is about 300 million years old (says Wikipedia). Perhaps you mean 30 million years.

I got the number from http://amsdottorato.unibo.it/3843/1/Cervellati_Claudia_tesi.... (in the abstract) that cites https://link.springer.com/article/10.1007/s11101-006-9033-1

Apparently is a very very old feature (even older than what I though).

Ah, ok. Yes, the last paragraph on page 1 says that the feature appeared before flowering plants, conifers and ferns split up. So yes, it is very ancient. Thank you.

I expect a more recent mutation to make the kernels more toxic than the edible part of the fruit, but I couldn't find an article that discuss that.

This is interesting, and a good point, but the existence of harmful natural mutations isn't by itself a refutation.

The idea I have (again, perhaps wrongly) is approximately that harmful-to-humans mutations make up a smaller fraction of the space of viable (i.e. allows the organism to survive at all) natural mutations, and a larger fraction of the space of viable transgenic mutations. A secondary point is that this is because the space of viable transgenic mutations is not constrained by the prior state of the genome, the same thing that makes transgenic mutations powerful also makes them risky.

So, I am (or I was, anyways) positing _fewer_ dangerous natural mutations, not necessarily zero.

I'm certainly less convinced that there's an important difference than I was yesterday, though, but mostly because the _accessible_ space of transgenic behaviors is evidently limited by investigator effort, which does not scale, so even if the _theoretical_ space is larger, it doesn't matter, we're not going to sample it.

Most of what I've read on this subject, from the scientific community, suggests that gene editing is safer than breeding for characteristics, because it's more targeted and controlled. If the concern is long-term viability of a species, then plants whose genes have been carefully edited are subject to all of the same evolutionary selection pressures as plants that have been altered through breeding.

Note that for instance the heavily-selection-bred Cavendish banana is currently facing possible extinction due to its susceptibility to a fungus. So on the one hand here you have exactly the problem you're worried about with gene-edited crops, and meanwhile gene editing is a possible solution to the problem.

I regret that I'm not well-enough versed in the science of this subject to communicate it better.

>>> I think it's tangential to the safety question -- actually-existing commercial GMO crops have been tested and demonstrated to be safe, that seems to be clear.

Actually, it's not that clear. They have been proven to not be unsafe, which arguably is a lot easier. But a lot of countries still ban them specifically because the "safe" part wasn't proven. Obviously this depends on the crop, as GMO means a lot of different things.

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