1.Comment from Dr. Brian John
2.Clarification from Dr. Doug Gurian Sherman

NOTE: These two items relate to a recent letter attacking a study published by the journal, Proceedings of the National Academy of Sciences (PNAS), which suggested widespread planting of Bt crops could have unexpected ecosystem-scale consequences - consequences that had not been properly investigated before the Bt crops had gained approval. The second item clarifies a specific point raised in comments on the letter by Dr. Gurian Sherman that we posted yesterday.
http://www.lobbywatch.org/archive2.asp?arcid=8501

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1.Comment from Dr. Brian John

The GM Cabal -- on the attack again

This letter, which throws around academic qualifications and affiliations like confetti, is clearly an attempt to pressurise the journal and to reprimand it for having the temerity to publish something of which they do not approve. It also suggests to me that these writers (only one of whom is apparently an expert in the relevant field) assume that the GM industry has a 'right of reply' to any article which suggests that there may be harm associated with GM crops.

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2.Clarification from Dr. Doug Gurian Sherman

Jonathan,

I was asked about the actual percentage of Monarchs calculated to be killed according to the Dively et al. study that I mentioned below. This person was rightly confused by the apparently high percentage of Monarchs that could be killed by the pollen (up to 24%), compared to the conclusion of Dively et al. and other studies that few Monarchs were at risk. I wrote below that more Monarchs were not actually killed because they were usually not present in corn fields when Bt corn produced pollen, but I neglected to include the actual calculation of Monarchs killed - 0.6%. This makes it appear that 24% were actually killed in the corn fields, which is not the case. In other words, up to 24% could be killed if present during pollen shed, but because most Monarchs are not present at that time, only about 0.6% are expected to be killed. Please clarify this so that there is no misunderstanding.

Thanks
- Doug
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Letter attacking PNAS study 'misleading' (19/11/2007)
http://www.lobbywatch.org/archive2.asp?arcid=8501

NOTE: Below Dr. Doug Gurian-Sherman, Senior Scientist at the Union of Concerned Scientists and former biotech specialist at the U.S. government's Environmental Protection Agency (EPA), comments on a recent letter attacking a study published by the journal, Proceedings of the National Academy of Sciences (PNAS).

The Rosi-Marshall et al study - funded by the National Science Foundation - found consumption of Bt corn byproducts produced increased mortality and reduced growth in caddisflies, an important food resource for higher organisms like fish and amphibians.
http://www.lobbywatch.org/archive2.asp?arcid=8358

The letter attacking the study is from the 'usual suspects' - Alan McHughen, Henry Miller, Klaus Ammann, C. Kameswara Rao, Ingo Potrykus, Piero Morandini, Chris Leaver, S. Shantharam, Mark Sears, and C. S. Prakash. With the exception of Sears, none seems to have any especial expertise in the area they're commenting on, and nearly all can be found in the GM Watch profiles (or by searching at www.gmwatch.org) of ardent GM promoters.

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Jonathan,

As you know, the recent paper in PNAS that shows possible harm to stream insects was attacked by a group of scientists in a letter to the journal editor. Most of the points that they raise in their letter are misleading, even while some of them are technically correct. Because of the subtleties involved, I have written rebuttal points that I sent to some friends. I thought that they may be useful to others. My points are in caps following the relevant sections of the letter written by the pro-GE scientists.

Doug

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Comments and letter to the editors of PNAS

A consortium of scientists signing this comment in a letter to the editors has analyzed the paper and came to critical conclusions, which seriously question the conclusions of the paper.

We are deeply concerned by the appearance in PNAS of a recent article, 'Toxins in transgenic crop byproducts may affect headwater stream ecosystems,' (10,1073 (2007)), by Rosi-Marshall et al., apparently funded by NSF. We recognize that it is not unusual for papers to be published with minor flaws or infelicities, even after peer review and revision, but the article by Rosi-Marshall et al. contains egregious methodological flaws and omissions, and presents conclusions not supported by the data.

We call your attention, in particular, to the following:

1) There is extensive evidence in the literature that corn pollen produced by currently available Bt corn varieties contain extremely low amounts of Bt toxin. This was shown in a series of six papers by top scientists published in PNAS after the Losey Bt corn pollen-Monarch debacle, an intensive and time-consuming effort to try to set the science straight (1). How many busy scientists and how much scarce money will we need to divert to calm this new scare?

IT IS SAD THAT THESE SCIENTISTS, ONE OF WHOM (MARK SEARS), WAS APPARENTLY HAPPY TO RECEIVE FUNDING TO PARTICIPATE IN THE MONARCH STUDIES (MAYBE HE WOULD SAY IT WAS HIS DUTY!), CANNOT APPRECIATE THE VALUE OF THE ADDED AGROECOLOGICAL KNOWLEDGE THAT THOSE STUDIES CONTRIBUTED. IN ADDITION (SPEAKING AS AN EPA SCIENTIST WHO WAS THERE AT THE TIME) THOSE STUDIES WERE NECESSARY TO INFORM EPA ABOUT ACTUAL RISKS FROM Bt CROPS IN THE FIELD. THE LOSEY PAPER ON MONARCHS WAS A PERFECTLY REASONABLE ONE. IN ANY CASE, THERE ARE SEVERAL ASPECTS OF THE MONARCH BUTTERFLY INCIDENT THAT ARE MISREPRESENTED HERE. FIRST, THERE WAS IN FACT A VARIETY OF Bt CORN, Bt176, THAT COULD INDEED KILL MONARCH BUTTERFLIES IN THE FIELD DUE TO HIGH LEVELS OF Bt TOXIN IN ITS POLLEN. IT WAS FORTUITOUS (I.E. HAVING NOTHING TO DO WITH EPA RISK ASSESSMENT) THAT THIS VARIETY WAS NEVER GROWN ON MORE THAN ABOUT 5% OF U.S. CORN ACRES, AND THEREFORE DID NOT HAVE A MAJOR IMPACT. THIS VARIETY WAS NOT RE-REGISTERED AFTER THESE RESULTS WERE DISCOVERED. SECOND, THERE WAS ENOUGH TOXIN IN THE POLLEN IN THE OTHER MORE WIDELY-PLANTED VARIETIES (MON810 AND Bt11) TO KILL MANY MONARCHS - UP TO ABOUT 24% ACCORDING TO A LATER STUDY (DIVELY ET AL. 2004). THE REASON THAT MORE MONARCHS WERE ACTUALLY NOT THREATENED WAS THAT THE CATERPILLARS WERE USUALLY NOT PRESENT IN CORN FIELDS WHEN POLLEN FROM CORN WAS PRODUCED. THESE DATA WERE NOT KNOWN BEFORE THE FIELD STUDIES REFERRED TO BY