> tests conducted by Oxitec prior to the experiment suggested that around 3 to 4 percent of F1 offspring would survive into adulthood, but it was presumed these lingering mosquitoes would be too weak to reproduce, rendering them infertile. These predictions, as the new research shows, were wrong … portions of the genome from the transgenic strain had “incorporated into the target population,” ... anywhere from 10 to 60 percent of mosquitoes analyzed featured genomes tainted by OX513A … the Oxitec scheme worked at first, resulting in a dramatic reduction in the size of the mosquito population. But at the 18-month mark, the population began to recover, returning to nearly pre-release levels. According to the paper, this was on account of a phenomenon known as “mating discrimination,” in which females of the native species began to avoid mating with modified males.
I hate mosquitos as much as the next bag of blood, but what I am not so sure about is the ability for Humans to understand the ecological ripple-effect killing off any large population of insect have on the overall ecosystem, environment and food-chain.
We may dislike mosquitos, but there are MANY critters out there that thrive on eating their larvae or their adults.
Just as humans have decimated the Monarch Butterfly's food/mating/hatching grounds (Monarch's almost exclusively rely on MilkWeed as a food and laying/hatching of their eggs. This "weed" grew from south america all the way through northern america, which is where the multi-generational-migration path of Monarchs occurs. By killing off MilkWeed with pesticides, as Humans don't find it an aesthetically pleasing plant, effectively destroyed the biological support infrastructure used for eons by the Monarch for their mass migrations up the corridor from Mexico north.
So - Sure, we don't like mosquitos, but I would not trust that we understand the true, long-term impact of eradicating them just yet.
There are multiple mosquito species in each area and these control efforts only target a couple of species that are human disease vectors. Even if these specific species went extinct it would not significantly impact other creatures that prey on mosquitos.
Previous eradication efforts used pesticides and impacts all mosquito species and lots of other creatures, as well. Using genetic targeting like this is much lower impact. The main question is whether it will be effective.
So one thing to keep in mind: it is estimated that half of all human beings who ever lived throughout human history were killed by mosquitoes.
I understand your argument, but at some point you have to say "I'm human, I care primarily about humans, I will do what it takes to help humans." At some point we get pragmatic, selfish, and we declare something our mortal enemy. I'd say the largest killer of human beings by orders of magnitude best qualifies. I say if we can eradicate mosquitoes that feed on humans we should do it.
The good news is that the plethora of ecosystems and niches in them that are filled and supported by mosquitoes is so rich with pathways that it is highly unlikely to cascade badly if they were eradicated. Particularly, we only target mosquito species that are disease vectors for human beings, and there are many many more mosquito species that target other animals or are not disease vectors for humans that those niches may very well be filled by other species of mosquitoes.
She's been ranting about genetically modified mosquitos for as long as I know her, claiming it cannot and never will work, mainly because mosquitos have an insane amount of offspring and a very short lifespan.
They adapt so, so, so quickly.
A male mosquito lives a week, a female mosquito a few months at best, and they produce 300-600 eggs per female mosquito on average. Can you imagine the exponential growth and recovery rates of these animals? It's like sharing your grandmother with 45000 cousins, and each of your grandmother's 299 siblings has 45000 grandchildren as well. It's a big family very quickly.
There are stories of countries who tried to eradicate mosquitos and reduced the mosquito population to 1% of what it originally was, only to jump back to 100% within two years (or so, my memory is hazy) after the program stopped because politicians had declared the program a success.
Mosquitos man. I'm not sure we'll ever get rid of them. They will probably outlive us.
Some years are different than other. Last five years were particularly hot and 2020 was the hottest year registered.
Not to mention the wildfires, or the speeding deliberate destruction of the rainforest in the last four years.
Removing trees will remove the rainclouds created by those same trees, and removing the rain means that the place will dry and eventually become arid. Not surprises here.
In both cases we can expect some effect on an animal that breeds on temporary rain pools and lagoons.
Thus, the alleged effect of modified mosquitoes can be zero, or much lower than we think. This effect will be temporary, because mosquitoes are facing similar problems and dry spells for millions of years and they still somehow survived.
That would be weird to go from 1% for 2 years to 100% in an instant. Instead, I will say confidently that it was 1% for an instant, growing to 100% over two years.
I don't remember which country it was. I think it was an African country, but I'm not sure. I did find an article [1] about the (failed) eradication of the Aedes aegypti mosquito in Brazil, that contains the following quote:
> In 1973, the Pan American Health Organization again declared that Brazil was Aedes-free. The second official eradication period did not last long. In 1976 and 1977, A. aegypti was found in Rio de Janeiro and Salvador, Bahia, and then in nearly all the Brazilian states.
So, at least three years in their case. Seems you need to eradicate the mosquito from all the neighboring countries as well, otherwise they'll just fly in and fill the void. If you're interested in what they did to declare Brazil Aedes-free (twice), the full article is worth a read:
I once mentioned the obvious flaw in the GMO mosquito plan to my Genetics professor, but he just waved his hand and said "Oh, these folks are smart - they'll figure it out."
It's good to know that my intuition was correct and the field is basically over-promising to local authorities so they can effectively conduct funded genetic experiments in the wild...
Oh, wait a minute... No I'm not... That's a f*ing disaster waiting to happen.
How is the Earth not entirely made out of Mosquitoes then? What are the things that currently limit their growth, maybe it would be good to find out and use those?
Female mosquitos need blood meals to produce eggs, and a place to lay those eggs which is safe from predation. Both steps can be somewhat controlled by preventing bites onto humans, and by removing standing water, but you will never prevent mosquitos from biting wild mammals or pets, nor will you ever get all of the standing water sources (one old tire could spawn thousands of mosquitos).
One of the biggest limits is weather and climate. Mosquitos don't exist here in New England for half the year, but if we increase the temperature by 2 C, we'll probably be facing them for 7-8 months and they'll rebound harder and faster.
Food. Mosquitoes need blood to reproduce (among other things) and there's a finite supply of that. This caps the population. A very rapid reproduction rate means that they can quickly go from any population size to the max capacity of the environment they are in.
A lot of things eat mosquitoes. A lot. Fish, other insects, birds, bats, other mammals. They eat ridiculous amounts of mosquitoes. A single bat alone can eat its bodyweight in mosquitoes every day.
> How is the Earth not entirely made out of Mosquitoes then?
Mosquitoes are a key species, that feed in turn thousands of other animals: fishes, spiders, predatory flies, bugs, bats, frogs, birds, shrews... etc and suffer heavy loses by that. And they are also pollinators. Mosquitoes are connected with everything and will support everything.
So messing with them is notoriously dangerous. Playing football with a nuclear bomb would be safer probably.
If I understood parent comment, it's that any unmodified mosquitos would quickly fill in any gaps from modified mosquitos who died.
What we need is a gene bomb. Create a gene that makes mosquitos more resistant to gene attacks, but 10 generations later creates infertility. Spend 10 generations dropping gene attacks to ensure those bomb'd mosquitos proliferate and reproduce.
Gene drives are a way to spread a modification to all of a population because the genetic change has more than a 50% chance of making it into a gamete, all the way up to 100%, so it multiplies up over generations.
And yes it can be combined with a generational ticking time-bomb.
If they literally never mix, it doesn't reach the population it isn't in.
But that's a bigger ask than you'd think. Stuff moves around, on its own, and often, on humans and human artefacts. Like for example, mosquitoes breeding in a puddle on a boat.
This is basically a worry people have about gene drives, that they will jump from places where they are wanted, to wild populations that are doing nobody any harm, and eradicate whole species.
Yes, the gizmodo.com article has this information.
However, the concerns about the critical publication are due to the very broad conclusions it makes. But the mere facts of:
- lasting genetic contamination of the mosquito population
- failure to erradicate the Aedes aegypti in Brazil
are they true?
> According to Oxitec, the “OX513A self-limiting gene does not persist in the environment,” and that the “limited 3-5% survival of the OX513A strain means that, within a few generations, these introduced genes are completely eliminated from the environment.”
That is about the self-limiting gene. How about the other genes?
I wouldn't expect them to not change the strains over such a longe period of testing. But I also expected that changes would be mentioned, so... although I am optimistic about GMO and I believe it is unavoidable, but this could have been more transparent for sure.
Why would the females choose the sexy Cuban mosquitoes? I always wonder this.
Maybe they sing better songs with its wings.
Or maybe, because being genetically different is attractive for females. The bigger the genetic mix, the more healthy, disease free and stronger the offspring.
Or maybe they aren't choosing and just have a random brief encounters with as many males as possible. This is a question for an entomologist, but I would not expect mosquitoes behaving as humans in a prom necessarily.
Mosquito females cannot submit genetic samples of potential mates to a sequencing laboratory. They cannot determine which of two males has a "bigger genetic mix".
It's really easy to anthropomorphize the mosquitoes or to anthropomorphize natural selection; we shouldn't ascribe that kind of agency to them.
Instead, reason about the consequences that we observe after the fact: perhaps the modified male mosquitoes are drawn from a different population than the local, unmodified males, and the groups have slightly different colorings. A random group of females might prefer the modified color, a different group might have no preference, and a different group might prefer the local color. After a few generations, the latter group will dominate.
That's not because the female mosquitoes or Mother Nature made any kind of effort to find mates with good genetic material. No such agency was present in the process. Instead, those random behaviors that incidentally resulted in selecting good mates were more likely to be passed down.
> Mosquito females cannot submit genetic samples of potential mates to a sequencing laboratory. They cannot determine which of two males has a "bigger genetic mix".
Of course they can, you don't need to sequence DNA to get an idea of genetic affinity, you have the phenotype.
I don't know about mosquitoes, but all higher animals obviously judge mates on genetics (based on the phenotype).
you're kidding. I mean to people of course all mosquito look the same. It is a top of anthropocentrism though to think that mosquito would not differentiate. The basis of selection is "best fit" (to bring in and/or bring up new generation), and the weakness to the point of infertility is naturally selected out very quickly.
Evolution quickly selects against reproduction or immediate survival failure, but this modification leads to successful male offspring which makes the scenario trickier.
Unless the modified mosquitoes are handicapped by something, they will be selected just like any other, as best fit metrics are superficial. Humans wouldn't be able to detect that a specific partner could only have male offspring unless it brought along visual defects.
If the population survives for many generations with a significant population of defect males, if there is a physical characteristic in the defect males, and if that can be detected by a mutation present in some females - the UV marker maybe? - then the female population should slowly be replaced by ones that select against the defective male. That's a lot of ifs though.
Then nature got natural selection backwards too. Mating discrimination was shown to be real.
Theorizing is great. But once there is evidence the reaction needs to be to adjust the theory instead of arguing away the effects that have been observed since they are inconsistent with the theory. "You're getting it backwards" is exactly that.
Mating discrimination is real, but redefining "attractive" mates isn't just a single mutation that is implied in survivors like regular "survival of the fittest".
Redefining behavior of a specifies is a hell of a lot more complicated, especially if it's not just a simple matter of making presence of a certain smell a turn-off.
> Theorizing is great.
And all we can do for a few years until we get the most recent results, all we can do to interpret them, and all we can do to iterate on them.
Right, and while interpreting them, we need to be cautious. Instead of seeing an effect and think "nah, doesn't fit my theory of natural selection, can't be, let's keep going" we should be more like "oh, this effect was not predicted by our theory, something fishy is going on, let's be cautious".
That was found as a result of the experiment, though. I think he was just pointing out why the expectation was missed (or not seen as likely enough) before the experiment started.
I don’t think it’s weird to assume mosquitoes won’t be able to tell the difference. It turns out that was wrong, I hope it’s taken into account in this experiment.
It’s also not guaranteed that a gene that makes you glow red under fluorescent light will be noticed by other mosquitoes, but we can probably toss that in the pile of growing evidence.
Although I 'trust' US, I cannot forget of the legalized bribing called "Lobbying". When $bn roll, politicians roll over. USA is also missing from the above list.
In this specific case, in the worst case, an aerial mosquito spraying plane can fix this in a couple of days, killing majority of insects in the area (even the beneficial ones) and the 'damage' is contained. It's not like they will evolve to become "Mimic" (https://www.imdb.com/title/tt0119675/) within a couple of weeks.
This is a very smart technology that was invented and does not exists in nature to my best knowledge. So you throw this unique genetic mechanism not against the mosquitos, but in fact you have evolutionary pressure against you. In the best case, they become resistant, in the worst case you end up with total other effects in total other organism that acquired this mechanism.
An nuclear bomb explosion is limited in location and time. This genetic mechanism, once released, is potentially unlimited in location and time. So serious question, what could possibly go wrong?
> Please don't comment about the voting on comments. It never does any good, and it makes boring reading.
Just make your points the best that you can, and you'll avoid downvotes about spending half your comment talking about downvotes or attacking "the education and intelligence of the average HN Reader."
> But at the 18-month mark, the population began to recover, returning to nearly pre-release levels.
That's the whole point. Scientists have to build in "rent-seeking" properties into the "solution" so that the company can make money in perpetuity.
Nobody is interested in solving mosquito problem once and for all.
Because modified males can't have offspring down the line, only females who mate unmodified males produce offspring, selecting for females who would mate with such. This might even hurt a company selling such a solution, because if they released a second batch, nobody would mate with them.
Obviously this only works if modified males show any external characteristics.
But even without all that, at some point the modified populace is going to die off, since that was the point, leaving only unmodified ones, before finally recovering.
From the article: "The genetically engineered males carry a gene that passes to their offspring and kills female progeny in early larval stages. Male offspring won’t die but instead will become carriers of the gene and pass it to future generations. As more females die, the Aedes aegypti population should dwindle."
Exactly. Your quote does not invalidate the previous statement at all. Per evolution basic theory, the gene most adapted to the environment and which produces more offsprings, survives.
Therefore, offsprings of unmodified mosquitos have twice the chance to reproduce, as both males and females can reproduce and both will yield unmodified males and females. I wouldn't know the rate, but even if slowly, unmodified strain will come back, unless extinct.
There need be no female preference for this to happen, but of course if they evolve to detect modified males it would accelerate the rate which modified mosquitos get extinct.
> tests conducted by Oxitec prior to the experiment suggested that around 3 to 4 percent of F1 offspring would survive into adulthood, but it was presumed these lingering mosquitoes would be too weak to reproduce, rendering them infertile. These predictions, as the new research shows, were wrong … portions of the genome from the transgenic strain had “incorporated into the target population,” ... anywhere from 10 to 60 percent of mosquitoes analyzed featured genomes tainted by OX513A … the Oxitec scheme worked at first, resulting in a dramatic reduction in the size of the mosquito population. But at the 18-month mark, the population began to recover, returning to nearly pre-release levels. According to the paper, this was on account of a phenomenon known as “mating discrimination,” in which females of the native species began to avoid mating with modified males.