There’s new news on this topic. Turns out that predation by dragonfly nymphs produces the observed results.

See, "Studies offer new insights into causes of deformed frogs", MinnPost.com, Aug. 17, 2009,
http://www.minnpost.com/stories/2009/08/17/10844/studies_offer_new_insights_into_causes_of_deformed_frogs

Interesting!

Andy.

“Noise from a local building site is being blamed for the death of around 270,000 American frogs at a nearby farm in south China, the China Daily reported on Tuesday.”

“According to the farm owner, Fu Yishin, the round-the-clock construction work killed his frogs one after another as every time there was a loud noise the frogs jumped.”

http://en.rian.ru/world/20090714/155523152.html

CCD is a modern artefact of mass media, but has actually been a crucial, critical, real-world problem that can be dated back to at least 1996 (in the US), if not earlier.

Bee-keepers, and the crops and farmers who depend upon them, are so desperate for a working theory of CCD that they’re now proceeding on the basis of experimental banning.

That is to say, ban this, ban that, see if that works. This has been praised as the “Precautionary Principle” at work, but fact is, even this approach hasn’t done any good.

Cheshire, if you have a novel theory of CCD that deserves a real test–and the world needs it–please describe it and I will post it at GMObelus as a world challenge.

Andy.

HOWEVER…it has not been conclusively proven that IAPV is the cause of CCD or if there are multiple factors working together. We’re still in the ‘WTF is going on’ stage.

Since you’re at ISU, I’d recommend talking to Mary Harris in the Entomology department because she studies bees. Not honeybees, but she knows her field very well and could point you in the right direction. You can contact me through my blog and I’ll give you more info.

Not to be a shameless self-promoter, but I kind of hit on IAPV in a recent post on beekeeping. I linked to a paper with more information about it.

http://ddr.nal.usda.gov/dspace/bitstream/10113/9288/1/IND43991544.pdf

Harris will bee able to give you more information.

Unknown pathways cannot be detected by any means comprehensible to human science. Suspected pathways can be tested, but that requires an hypothesis as a starting-point. That is, a starting-point from some existing knowlege.

Perversely for you, but obvious to scientists, is that the only way “unknown mechanisms” can be tested is via the “unknown test”. Perhaps, some day, someone will develop a comprehensive test to determine the effects which ensue via unknown causalities.

Personally, I view that possibility as so impossible as to render further speculation as far beyond the scope of the genre known as science fiction. To be kind, I will say, your suggestion is so far beyond any credible conception of human science that it must relegated to the domain of nonsense — until, of course, you reveal your unknown test, which reliably detects the unknown pathways which lead to certain results.

What I say about gut flora is not an “hypothesis”. It works, and that is why the antibiotics are used in animal feed. You might envision the availability of food to farm animals as the “limiting factor”, but the fact is, what’s eaten is only relevant to the extent that the nutrition is *bioavailable*. If gut bacteria are consuming nutrition to their own advantage, thereby depriving the animal, you don’t want those critters in your gut.

Or, in the gut of the cattle you feed in order to feed… and, so forth.

As for your weak defense of biofilms, the best you can say is that some multicellular organisms, such as lobsters, manage to keep them at bay.

Many thanks. I, personally, and on behalf of many other friendly organisms, are thankful that we have developed internal defenses against what humans describe as slime.

Andy.

Unknown mechanisms can be tested. After they are tested they are not unknown. Every pathway that is now known was at one time unknown.

The mechanism(s) by which antibiotics increase growth rate, accelerate sexual maturity and increase feed efficiency remain unknown.

http://cmr.asm.org/cgi/content/abstract/16/2/175

Your hypothesis that it is due to selection for more efficient gut flora is non-physiologic. Why would more efficient gut flora not result in greater bacterial growth? In any case farm animals are fed ad lib, they can always eat more to increase growth, so food is not the limiting factor in growth rate. Animals can increase food consumption rate and increase conversion to biomass (as during lactation), so digestion capacity is not limiting. How does that affect the rate of sexual maturity? Only via endocrine disruption.

Only biofilms containing pathogens can cause disease. A biofilm that does not contain pathogens cannot cause disease. There are no reports of an “infection” being caused by ammonia oxidizing bacteria. Ammonia oxidizing bacteria do form biofilms on the surfaces of organisms such as lobsters. They form biofilms on other organisms too.

I’ll answer your points in order.

The effects via unknown pathways are not detectable by any method known to science, because unknowns cannot be tested. The vast majority of unknown pathways will remain unknown forever, because the vast majority of them simply do not exist.

The mechanism by which giving antibiotics to farm animals causes them to grow larger, faster, is that the antibiotics select in favor of the digestive flora in the gut which convert feed more efficiently. More efficient flora = better feed conversion = faster weight gain.

Disruption of bacterial biofilms is crucial to the health of higher organisms. Lower populations of unicellular organisms can be beneficial, such as in the digestion of food. At higher populations, at the point where the unicellular organisms form a biofilm on, or in, the body or plant, the cells in the biofilm actually begin cooperating to ensure the biofilm’s survival. By up-or downregulating specific gene sequences, they engage in specialized functions within the biofilm–making the infection far more devastating. Since bacteria, even at this level of organization, are fundamentally stupid, this cooperation–which means competing with the host organism, or even digesting its tissues, can very quickly lead to the death of the host organism.

Basically, a plant or animal with a biofilm in or on it is either dead, or dying.

There are beneficial biofilms, such as in industrial processes involving bioreactors, or in the environment, where they perform what are loosely called “ecosystem services”.