Here at ScienceBlogs, we’ve regularly posted about the thorny issue of
antibiotic overuse, and the subsequent antibiotic resistance.
This is a good example of evolution in action; it’s also a
good reason why we need to study and understand evolution.
But antibiotic resistance is not the only such example. The
same principle applies to herbicides and weeds.
Naturally, a good example comes to us courtesy of
the company that href="http://www.vanityfair.com/politics/features/2008/05/monsanto200805?printable=true¤tPage=all">everyone
loves to hate. (There is even a movie now, href="http://www.smirkingchimp.com/thread/13587">The
World According to Monsanto. It’s on
Google video, href="http://video.google.com/videoplay?docid=-842180934463681887">here.)
You see, Monsanto has made a lot of money by engineering crops that are
resistant to their most popular herbicide, href="http://www.monsanto.com/monsanto/ag_products/crop_protection/products/roundup_power_max.asp"
rel="tag">Roundup® ( href="http://en.wikipedia.org/wiki/Glyphosate" rel="tag">glyphosate).
The idea is that you can plant these crops, then bathe the field with
Roundup. The herbicide kills the weeds, but the crops are
Any biology sophomore could tell you, that sooner or later, you will
get Roundup-resistant weeds.
Now it has been documented. Roundup was
in 1976. In 1996, Monsanto introduced href="http://sandwalk.blogspot.com/2007/03/roundup-ready-transgenic-plants.html">Roundup-ready
soybeans. No Roundup-resistant weeds were detected
before the widespread use of the resistant crops. Even then,
it took a while. But now…
Johnsongrass, the latest entry to the lengthening
list of glyphosate-resistant weeds — in both Arkansas and
Mississippi — was announced in mid-March. It is the first
glyphosate-resistant warm-season grass found in the United States.
“We’re not trying to push resistance in these
weeds,” says Bob Scott, Arkansas Extension weed specialist.
“But there’s close to 5 million acres of Roundup
Ready crops that get two or three applications of Roundup every season.
Plus, we’re using Roundup as a burndown.
“It’s inevitable that such weeds are produced.
It’s hardly a surprise.”
Johnsongrass found in a Crittenden County soybean/wheat field is the
fifth glyphosate-resistant weed discovered in Arkansas. The others:
horseweed (also known as marestail), common ragweed, giant ragweed and
Palmer amaranth, a pigweed…
( rel="tag">Sorghum halepense) is
notable because is it an href="http://www.invasivespeciesinfo.gov/plants/johnsongrass.shtml">invasive
species that can be href="http://en.wikipedia.org/wiki/List_of_plants_poisonous_to_equines">toxic
In the long run, it may not matter, since industrial-scale agriculture
may not be around much longer. The thing is, the genetic
modifications are now in the wild. There is no way to put the
genie back in the bottle. It is not possible to fully
anticipate the consequences.
One could argue that the benefits outweigh the risks. After
all, the more food we can grow, the more people we can feed.
It would be nice to eliminate hunger.
But, what if our ability to engage in industrial farming is
time-limited? that is, what if we can only do it for a few
decades, before the petroleum necessary for this kind of farming
becomes too scare to be used for this purpose? What is no
alternatives are found, or if they are found but not deployed?
Then, we will have grown a population of humans that is too large for
the planet to support. Many of them will die. Sure,
some people will have made a lot of money off the scheme, but does this
really make sense?