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."
Life finds a way
Is this a surprise, that nature can route around humans? Seriously, this was expected. However, all this means is that Monsato and other evil corporations like it who create GM seeds now have an opening for a new product to develop and sell, for an even higher price. And they will get this higher price because the "old" GM seeds are not successful any more. And the cycle continues...
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?
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.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
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.
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.
#DeleteChrome
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.
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."
Glad I could help.
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?
To try to get some insight on how many genetic changes there are in insects I churned a few numbers:
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.