Item — HN Reader

I have a question for folks who have background in interventions like these.

Isn't there a risk that the artificially introduced reproductory pressures would select for screwworms that produce males that are resistant to radiation.

My chain of reasoning is that not all the of the irradiated males would be completely sterile. If so, then the next generation would be a mix of hatchlings of not radiated parents and those parents who have not been completely sterilized in spite of radiation -- thereby increasing the proportion of radiation resistant varieties, assuming resistance is an inheritable trait. These may then find themselves at the input side of sterile male generation factories.

The intervention obviously worked, but was that because steps were taken to counteract the possibility of raising radiation resistant varieties.

BTW the article was a great read.

3 comments

Not knowledgable, but irradiated flies should not be expected to be irradiated again. There are 3 population pools:

1. The Factory spawning population - This is self-sustained, and never encounters radiation.

2. A subset of the spawned males from the factory population are irradiated, making them sterile.

3. The wild population, consisting of the sterile males + wild males + wild females.

If for some reason the sterile population is not fully sterile (unlikely), then maybe there is a gene that helps for radiation resistance, but the children of that strain will not encounter radiation, so it fades away.

The factories are not going out to the regions where the flies are deployed to get new fly studs.

There can be selection pressure for females to mate with multiple males.

Releasing sterile males only works for species that mate only once or at most twice, and rapidly falls off in effectiveness for species where the females mate many times.

Your 1. By itself would mitigate the risk I think.

I'm not sure radiation resistance is really a thing. Radiation causes physical damage, it's not like a virus or bacteria that an organism can potentially fight off with an immune response.

The few males that might survive the gamma exposure with intact fertility are probably just ones that didn't get a full dose.

It is rather amazing to me in fact that it's possible to sterilize the males without killing them.

Everything is a thing. Immune systems are, when all is said and done, physics. Simpler forms of death tend to be harder to evolve resistance against, but given enough generations it will happen. For example, microorganisms regularly evolve increasing resistance to sterilizing chemicals, such as enterococcus faecium evolving resistance to isopropanol, various species of bacillus increasing their resistance to hydrogen peroxide, pseudomonas evolving resistance to benzalkonium chloride, etc.

Surprisingly, it is a thing.

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

Even in computation.

This might be a way to adapt to radiation: https://en.wikipedia.org/wiki/Radiosynthesis_(metabolism)

Couldn't there be genes that help with repairing the radiation induced damage ?

From what I have read, flora and fauna around Chernobyl seems to have acquired degrees of radiation tolerance.

BTW I am a complete ignoramus in these matters.

Yes. There isn’t much evolutionary benefit and it would be insanely calorically expensive, but there’s no reason a creature couldn’t evolve some kind of DNA repair or something to that effect.

Iirc, elephants almost never get cancer, nor do lobsters.

There are already bacteria found near Chernobyl which consume radiation.

I'd expect that if females start to breed more than once it would represent a problem. It's surprising it hasn't happened yet (for the ignorant of the field that I am at least)