Insects Rapidly Becoming Resistant To GM Corn

DrHeasley writes "BT corn, which contains the DNA for Bacillus thuringensis toxin, was once hailed as the final solution for insect predators on this valuable crop. Now it turns out that insects, and evolution, are smarter than we thought, and the corn that contains the built in pesticide is no longer reliably protected."

Comments

Jeff Goldblum

[Anonymous Coward]

Life finds a way

Re:Jeff Goldblum

[Samantha Wright]

It's been doing this for millions of years. Plants evolve pesticides constantly. There are species of cacti that grow in perfect grids because they toxify the soil against even their own seedlings (a common trick amongst trees, to prevent crowding) and it's why wild almonds contain cyanide. The only real surprise is how fast the insects coevolved—but perhaps, given the rate of adaptation of bacteria to antibiotics, that's foolish of us.

Still, don't take this as an excuse to be ecologically destructive. Species that are already under stress don't have much leeway, and any shot to biological diversity is bad for the biosphere's durability as a whole, excepting perhaps idiotic birds like the kakopo.

Re:Jeff Goldblum

[Samantha Wright]

As an evolutionary biologist it is my sworn duty to make fun of helpless species that evolved to fill an ecological niche in the absence of predators. Like Walmart shoppers.

Re:Jeff Goldblum

[OeLeWaPpErKe]

Just so some accuracy can be in here. Life, as in DNA replication, exists for about 3 billion years. The solar system for about 4.5 billion years (our sun is third generation, in other words, 2 solar systems were destroyed before ours was created in roughly the same place), and earth somewhere near 4.4 billion years, although it could have been much smaller than today until about 4.2 billion years.

That "island species" (technically races, not species) die out when reunited with their long lost mainland brethren is not exactly news. It's what's happening to the human species right now. In general, without natural borders, different races are impossible within a species. The fact that we have both global travel and different races is an exceptional situation, and a temporary one (in ~500 years, maybe less, there will only be 1 human race left, unless global travel ends before that time). It is not known which race that will be, but if other island species evolution patterns are any indications, whatever race survives will look a lot like the original human race. It would be interesting to see whether the remaining race would be black or not (if not, that would be a strong indication that the original humans in Africa were not actually black before the races split up. My money's on that they weren't black (cause primates have white skin), but it could very well depend on the exact timing of the split).

My biggest complaint about food crops, rather than their GM-ness (success or failure) is that once we get a "good" strain, we keep cloning it instead of continuing the process via selective breeding. So while each generation of insect improves against the crop, the crop defends damn-near exactly the same way; I suspect that may have reduced the time needed for adaptation as well.

No offence, but this is a trivial, trivial complaint. Don't you think that GM researchers *also* stimulate evolution in those plants ? Also, for extremely obvious reasons predatory species cannot totally wipe out the species they seem to be destroying. Predatory species are fundamentally limited to about 1/500th of the biomass of their victim species (or -usually- much less), except in the extreme short term.

Re:Jeff Goldblum

[ATMAvatar]

Don't you think that GM researchers *also* stimulate evolution in those plants ?

No, I don't. Many if not most GM plants are rendered sterile so that you are forced to purchase new seeds from year to year, thus making further evolution impossible. In the off-chance that some GM plants manage to produce offspring, the farmer involved (intentionally or no) sued and the crops destroyed.

Re:Jeff Goldblum

[FirephoxRising]

I'm amazed that anyone is surprised at all. If you have a selection pressure (the BT corn), then eventually (and not that long, insects breed fast) one mutation will arise that allows the insect to eat it, breed and pass on the resistant genes. Soon the new genotype is the dominant one, and the corn is lunch. They'll need to use toxic sprays to wipe out these populations and then stop using BT crops constantly, if you break us the cycle, the BT eaters will have no advantage and possibly be at a disadvantage compared to the other insects, and the population will not be composed of resistant members. The organic movement has been saying that this would happen since they first announced the new GM corn. BT is best used as a spray in combination with other management strategies. Idiots. The amazing thing is that they want to sue neighbouring farmers if the GM genes cross the boundary (when they said it wouldn't) and they are surprised when organic farmers sue them back if they lose their accreditation due to the contamination. Talk about wanting it all ways!

Re:Jeff Goldblum

[Ihmhi]

As an evolutionary biologist you would probably appreciate this the most out of anyone.

Re:Jeff Goldblum

[The Master Control P]

There's no disease pressure to speak of on Western populations, yet the developed West is characterized by zero to slightly negative population growth.

If you want to get Africa's population growth in check, eliminate disease and eliminate famine. One you take away the visible and very real threat of most of a mother's children not living to reproductive age, she'll stop having half a dozen of them.

Re:Jeff Goldblum

[Lumpy]

http://www.organicconsumers.org/Monsanto/farmerssued.cfm

http://planetgreen.discovery.com/food-health/monsanto-sues-pennsylvania-farmer-for-saving-seeds.html

http://www.nytimes.com/2003/11/02/us/saving-seeds-subjects-farmers-to-suits-over-patent.html?pagewanted=all&src=pm

I can find you literally HUNDREDS of articles about farmers getting sued by GM seed makers. Only a raving lunatic would say "they dont sue farmers"

Re:Jeff Goldblum

[Runaway1956]

Imagine that. We tamper with nature, and nature tampers right back. And, we're kinda stuck with a monoculture. I've read, and even posted on /. a time or two, about the many varieties of vegetables that are virtually extinct now. Potatoes. I think we have maybe 5 varieties, out of hundreds that were common in the 1800's. Just one super resistant blight that targets one currently grown variety can put mankind in real hardship. The strain of corn being cited probably accounts for more than 60% of the corn grown in the US, and possibly 40% or more of the corn grown worldwide. Kill it, and people are going to go very hungry.

Monocultures are so WONDERFUL - for the people who are extorting money out of that one culture!

Laugh at me, one and all. But it is within reason that these monocultures may put mankind's survival at stake one day.

Why is this even a surprise?

[idbeholda]

Everytime we've hailed a one-shot approach to these types of problems, the same thing happens. Look at antibiotic resistant strains of bacteria and the like. Do you really think this is going to be any different?

Re:Why is this even a surprise?

[Samantha Wright]

We didn't expect it to happen so quickly, that's all. Bacteria evolve much more rapidly than insects: E. coli splits once every 8 hours under optimal conditions in colonies of millions of cells, and may mutate up to 0.003% of their genome with each cell division under stress. That's a lot of brute forcing power. Insects, by contrast, have much more elaborate and stringent eukaryotic mutation controls, and most species take a couple of weeks to hatch.

Re:becoming resistant or...

[Samantha Wright]

It's a common abuse of semantics in science, but you're correct. Insects aren't spontaneously becoming resistant, their descendants are being selected for resistance. The belief that major evolutionary adjustments can occur within a single lifetime is an abandoned evolutionary theory called Lamarckianism, the classic example of which is a proto-giraffe's neck stretching out to reach higher and higher leaves, and this stretchedness being passed on directly to the offspring (as if someone who becomes muscular as an adult will pass on their musculature directly to their children!) Incidentally, there actually are two evolutionary elements that function according to a Lamarckian model: epigenetics (censorship applied to DNA that can be changed in response to environmental stressors) and culture (many mammals and birds, amongst others, can pass on innovations to their offspring through teaching.) It appears that an organism that can change itself during its lifetime is preferable to one that must evolve over generations, but the good ol' nucleotide tape is stuck in Mendel mode.

Re:Surprise?

[Samantha Wright]

It may amuse you to learn how the Monsanto people "engineered" their genetically modified and patent-protected seeds.

They hit them with random mutagens until they found something that was resistant to Roundup. And then they bred them like pedigree cats to enhance the effect. The grass genome (from which corn, wheat, and a number of other crops are derived) is absurdly complex, believed to contain four to six times as many genes as the human, and comes in five copies. Engineering it is very hit-and-miss. So they didn't even bother. Instead they patented the outcome of a directed natural process. It's like patenting the domesticated cow genome. (The grass-eating variety, not the mother-in-law variety.)

Thanks, Monsanto!

[93 Escort Wagon]

Organic gardeners saw this coming from the get-go - I remember a Mike McGrath (then editor in chief of Organic Gardening) editorial predicting it. Heck, we'd already seen this happen with badly managed organic farms - back in the 1990s, resistance had been seen in Diamondback moths on Hawaiian farms that sprayed B.t kurstaki repeatedly rather than just when monitoring indicated a need for spraying.

The continued usefulness of organic/botanical pesticides has, in large part, been due to their lack of persistence in the environment. Inserting those genes into plants is basically making the pesticides persistent, which (obviously) leads to much quicker development of resistance on the part of the pests.

The part of me that's a cynic wonders if this is what Monsanto had in mind all along... one less organic competitor to their stable of proprietary chemicals.

Maybe some of the worms were already resistant

[erice]

We didn't expect it to happen so quickly, that's all. Bacteria evolve much more rapidly than insects: E. coli splits once every 8 hours under optimal conditions in colonies of millions of cells, and may mutate up to 0.003% of their genome with each cell division under stress. That's a lot of brute forcing power. Insects, by contrast, have much more elaborate and stringent eukaryotic mutation controls, and most species take a couple of weeks to hatch.

Which probably means that some small fraction of the population was already resistant when the "experiment" began. No need to wait for a lucky mutation. Just apply strong selection pressure and the trait quickly spreads.

Re:Surprise?

[kdemetter]

You are on to something there :

- a patent on GM seeds only lasts for a few years
- It only takes a few years for the insects to overcome the GM corn's resistance
- new GM seeds are invented in the mean time , which are again patented

Using this technique, you could trigger a targeted evolution in insects, making them much more dangerous for non-GM crops, effectively forcing farmers to use the GM seeds.

Not Monsanto's only large GMO problem

[plsenjy]

A couple months ago I drove Dr. Don Huber of Purdue from the airport to a field day (ag industry for product demo) being put on by my family's non-GMO seed firm in the Upper Midwest. He of course had already been hearing of this problem for a while (the plant pathology/development community is pretty small, and when something new crops up everyone is in the loop) but was (and still is) much more concerned with a different pathogen that's been cropping up slowly for the past few years at higher and higher rates. Personally, I am not a seedsman and can't explain it very well, besides saying that it's a bacteria that he has been linking to Roundup Ready plants (Roundup Ready is a gene that Monsanto inserts in all sorts of plants in order to make them resistant to a pungent herbicide, Roundup) that causes infertility in everything it touches and we're unsure of how to deal with it. This website explains the problem pretty well (ignore the activism associated with it, it should just be used as a teaching point) http://action.fooddemocracynow.org/sign/dr_hubers_warning/

What's really chilling is that our non-GMO firm does very well outside the US. This is because most country's will not allow GMO's to be planted in their country due to their lack of long-term testing of effects on humans. I can't remember the exact regulation but in the EU they only allow something like 10-15% of their foodstock to be GMO. In Japan they're not allowed to be planted at all. My dad (the non-GMO seedsman) always likes to tell this anecdote - that when asked why they won't plant any GMO corn, the Japanese grainsman says, "We are conservative with our food. We want to see what it does to your children's children before we'll even consider it."

Refuge row regulations

[dbc]

My brother is a farm manager in Iowa, and he told me that Iowa has regulations where either 10% (or 20%, I forget which) of your rows must be "refuge rows", that is, if you plant a GMO variety, you need to plant non-GMO refuge rows in the same field so that the insects (or fungus or whatever you are fighting) has some place to go live where it then should not develop resistance. Overall it is still a win, because the GMO rows are more productive, and you can plant your refuge rows on fence rows and turn-around rows that never yield as well anyway.

So... does anyone know of other states have refuge row regulations? Or is the % of refuge rows just not sufficient?

Re:Surprise?

[robotkid]

It may amuse you to learn how the Monsanto people "engineered" their genetically modified and patent-protected seeds.

They hit them with random mutagens until they found something that was resistant to Roundup. And then they bred them like pedigree cats to enhance the effect. The grass genome (from which corn, wheat, and a number of other crops are derived) is absurdly complex, believed to contain four to six times as many genes as the human, and comes in five copies. Engineering it is very hit-and-miss. So they didn't even bother. Instead they patented the outcome of a directed natural process. It's like patenting the domesticated cow genome. (The grass-eating variety, not the mother-in-law variety.)

This is incorrect, my biochem prof many moons ago consulted for Monsanto and gave us a nice lecture on how this was accomplished. Basically, Roundup (glyphosphate) inhibits an enzyme in most plants that is required to synthesize essential amino acids from glycine. It turns out certain insects have an orthologous enzyme that is not inhibited by glyphosphate - this was spliced into the "roundup ready" seeds. This is how the engineered strains can also have high yield; if you simply tried to randomly mutate glyphosphate resistance, chances are you'd also reduce the efficiency of the enzyme itself and produce a pretty sickly crop with poor yields. The problem with weeds is that even a sickly growing weed can mess up your crop.

http://en.wikipedia.org/wiki/Roundup_(herbicide)#Genetic_engineering

Genetic engineering is certainly not elegant, it's mostly cut-and-paste jobs, but you only use directed evolution to fine tune things as it justs gets stuck in a local evolutionary minimum.

Rate of evolution - guesstimate

[Alain Williams]

To try to get some insight on how many genetic changes there are in insects I churned a few numbers:

1. * Life cycle time is takes a full year for most insects
2. * Number of offspring per female 100 - varies a lot
3. * Number of insects per acre is 10^8 (100 million)
4. * Number of acres grown under GM crops 3x10^8
5. * Mutation rate is about 10^-8 per base pair per generation
6. * The number of genome base pairs 1.4x10^8 (fruit fly)

Multiply that and you get 10^18 insect offspring per year; a mutation rate of about 1 per individual per generation. So the number of mutations is a very large number. This means a large number of ''natural experiments'' done, one of which may result in an insect a bit more resistant to a GM crop, this will give the insect an advantage and so be able to have more offspring all of which carry the advantageous gene. So advantageous genes spread rapidy, through sexual reproduction are combined with other genes and the best combinations flourish.

WARNING: very rough calculations, most insects die before they have the chance to reproduce and so most mutations are 'lost'. The numbers that I obtained are very likely wrong - but even if each one is wrong by a factor of 100, it doesn't make a huge dent in a very large number.