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Biotech Science

Insects Rapidly Becoming Resistant To GM Corn 368

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."
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Insects Rapidly Becoming Resistant To GM Corn

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  • by Samantha Wright ( 1324923 ) on Thursday December 29, 2011 @03:19AM (#38523544) Homepage Journal
    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.
  • by Hartree ( 191324 ) on Thursday December 29, 2011 @03:35AM (#38523602)

    Maybe marketing types. But I seriously doubt many entomologists or crop scientists were saying that this was the "final solution" to rootworm or any other pests.

    In fact, they've been advising using non-bt planted in a certain number of acres near the bt ones to slow down the development of resistance.

  • Re:Jeff Goldblum (Score:5, Informative)

    by OeLeWaPpErKe ( 412765 ) on Thursday December 29, 2011 @04:26AM (#38523764) Homepage

    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 (Score:5, Informative)

    by ATMAvatar ( 648864 ) on Thursday December 29, 2011 @04:37AM (#38523810) Journal

    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.

  • Evil government! (Score:4, Informative)

    by thule ( 9041 ) on Thursday December 29, 2011 @05:28AM (#38523964) Homepage
    How is Monsanto evil in this case? One of the big reasons cited in the article for farmers abusing the BT corn is the market price of corn is very high. Not mentioned in the article is the reason why it is so high. My cousin informed me that he is going to sell off the bit of corn they don't use for cash this year. Why? The government has been subsidizing the corn/ethonal in at least three different ways, exaggerating the price. Why wouldn't a farmer plant and sell of as much as he can and cash in on the high prices? The only reason they are able to do this in the first place is the high yield of corn crops since the 1960's (150-200 bushels and acre compared to only 50/acre years ago). Would we even consider burning corn in our cars if we were not able to realize current yields? If the government wasn't distorting the price, then normal supply in demand would limit the interest in planting too much corn and flooding the market.
  • by dbc ( 135354 ) on Thursday December 29, 2011 @06:23AM (#38524178)

    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? (Score:5, Informative)

    by robotkid ( 681905 ) <> on Thursday December 29, 2011 @06:38AM (#38524220)

    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. []

    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.

  • by Alain Williams ( 2972 ) <> on Thursday December 29, 2011 @06:43AM (#38524242) Homepage

    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.

  • Re:Jeff Goldblum (Score:5, Informative)

    by OeLeWaPpErKe ( 412765 ) on Thursday December 29, 2011 @06:54AM (#38524282) Homepage

    Think about this for a second. How are these seeds grown ? Sterile ? How are the genes developed ? When are they rendered sterile ?

    Needless to say, evolution is used in these plants. They introduce a few million random mutations while getting the plants infected with DNA rewriting viruses containing interesting genes (just like in the real world, incidentally, except they are the ones picking the genes instead of random chance). From the results, the extremely large majority is substandard. Then they select the best ones, grow massive quantities of them, and repeat the process (does this process perchance remind you of something ?).

    Then repeat this entire shit 500 times, and then finally render the final batch of the plants second generation sterile, which is then sent out. In reality GM "manipulation of plants" is not that different from accelerating normal evolution under specifically chosen circumstances (ie. what humans have been doing to farm plants for 20k years, just better and faster).

  • Re:Jeff Goldblum (Score:5, Informative)

    by Lumpy ( 12016 ) on Thursday December 29, 2011 @08:58AM (#38524718) Homepage [] [] []

    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 (Score:4, Informative)

    by gslavik ( 1015381 ) on Thursday December 29, 2011 @09:31AM (#38524866)

    I believe these were some of the older crops before they were rendered sterile. It has happened though. GM-crop companies (Monsato, I believe) have sued farmers under the DMCA for using the produced seeds of plants which Monsato sold seeds for. There was a case where a farmer was sued even though the neighboring farmer used such plants and pollen from those plants got carried over. Here's a recent one: []

  • Re:Jeff Goldblum (Score:3, Informative)

    by Hatta ( 162192 ) on Thursday December 29, 2011 @10:08AM (#38525224) Journal

    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).

    We already have but one race. There is more genetic variation within one troop of chimpanzees than there is among the entire human species. A random african and a random european have as much DNA in common as two random africans do. Race is genetically meaningless.

  • Re:Jeff Goldblum (Score:5, Informative)

    by painandgreed ( 692585 ) on Thursday December 29, 2011 @05:03PM (#38530798)

    Bananas! We may very well see the extinction of bananas in the near future. We bred all the seeds out of them and we grow only one kind.

    Well, Americans only eat one kind, the Cavendish. We used to eat the Gross Mike ("Big Mike") until such a blight did kill them off. There are plenty of other bananas, but they are typically starchy and not what an American thinks of as a banana. However, even if the Cavendish does get wiped out, there is apparently another banana ready to take it's place, but it has a more apple flavor to it. In a generation nobody will know, just as we now only have reports that Gross Mike tasted much better than the Cavendish.

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