Does
genetically engineered corn pose a threat to monarch butterflies?
Dear John,
You and other anti-biotechnology activists
make much of studies that seem to suggest that pollen from genetically
engineered corn could possibly harm monarch butterflies. Indeed,
the Campaign to Label Genetically Engineered Foods, which you support,
displays the monarch butterfly as its logo, presumably because of
the alleged threat. I hope that you have the courage to admit that
you were wrong, in view of the recently released report by the National
Academy of Science stating that the impact on monarch butterflies
is "negligible."
- A scientist who values fact over fiction.
Dear Scientist,
Thank you for your letter. Reading it, I remembered Plato's remark:
"We are not simply contending in order that my view or that of yours
may prevail, but I presume we ought both of us to be fighting for
the truth."
The first research showing that pollen from genetically engineered
corn could be fatal to monarch butterflies was done at Cornell University,
and published in the widely respected journal Nature in 1999. The
following year, research at Iowa State University corroborated these
findings. Now we have this recent report which, as you correctly
report, seems to suggest otherwise. What accounts for this discrepancy?
For one thing, this recent report, which seemed to show little or
no harm to the butterflies, studied the effect of pure pollen from
genetically engineered corn plants. The Iowa State study that found
harm, on the other hand, studied pollen containing pieces of "anthers,"
the part of the plant that produces the pollen. Anthers tend to
be shed by the plant along with the pollen, and contain much higher
levels of toxicity than pure pollen. Since anthers are part of what
is naturally deposited in the field, it can be misleading to concentrate
solely on pollen and rely exclusively on pure pollen tests. Anther
and pollen mixtures are more realistic.
There is another reason why the recent research to which you refer
might have come up with a misleading underestimate of the danger.
It looked only at short-term exposure, and ignored the implications
of what happens to monarchs when they are exposed to genetically
engineered corn pollen over time.
Unlike the earlier studies, the recent report was partially funded
by agricultural biotech companies.
The biotech industry frequently implies that those who question
it are reacting from emotion rather than reason, and that concerns
about the safety or health of genetically engineered crops are irrational
and exaggerated. But the more I've learned, the more I've seen that
there are bona fide issues here of scientific uncertainty, health
risks, and environmental dangers. And the more it seems to me that
it's not the people who challenge genetic engineering who are blinded
by emotion, but rather those who want to rush headlong into it,
reckless with the excitement of overcoming Nature's most ancient
and inviolate boundaries.
Yours with great respect for truth,
