A perspective on ecological consequences of GM crops

This post contributed by ESA member Sean Hoban, a post-doc in conservation genetics at the University of Ferrara, Italy. In the opening pages of his book, Omnivore’s Dilemma, Michael Pollan quotes agrarian writer Wendell Berry in reminding us that, “Eating is an ecological act.”  Simultaneously, eating is also a political act.  Indeed, in the past year, headlines about local food and the US Farm Bill have reminded us of the interplay between agriculture, government policy, and the environment.  Food choices are complex, requiring diverse knowledge to understand the consequences of our choices, especially regarding genetically modified organisms (GMOs), one of this years’ most hotly debated topics.  GMOs are crop varieties that have been engineered to carry genes for desirable traits, taken either from other species or synthesized in the laboratory.  Such crops now make up more than 90% of sugar beet and cotton grown in the USA, and 88% of corn. Most of the debate about GMOs (understandably) centers on human health, but GMOs also influence other aspects of social-ecological systems.  This post looks at a few basic ecological concerns, which have not received much mainstream attention.  The Ecological Society of America (ESA) published a position statement in 2005 that explains these and other issues in detail.  Wikipedia has a thorough article on many benefits and costs of GMOs. While GM crops have been around since the mid-1990s, a lot is happening in 2012.  In November, Californians will vote about GMO labeling, while recently a similar “Right to Know” bill was abandoned in Vermont (after legal threats from agribusiness titan Monsanto).  Russia recently banned imports of GM corn based on a recent controversial French study that claimed to have demonstrated a link to cancer.  And next year, the US Supreme Court will consider a lawsuit between Monsanto and an Indiana farmer who unknowingly planted patented GM seeds. One big ecological concern is the potential for GM traits to “escape” into other species by hybridization.  A common GM trait is resistance to particular types of herbicides, such as glyphosate, so strong herbicides can be used to control weeds without affecting crops .  Other GM plants produce their own insecticides, such as Bt toxin, to prevent pest damage and require less pesticide application.  Future GM crops might be created to have higher nutritional value (e.g. to produce particular vitamins) or tolerate environmental stress.  The worst-case scenario sometimes portrayed is that such genes could escape into plants outside cultivation, creating super weeds (weeds resistant to herbicides) or otherwise altering a plant’s ecosystem role or relative fitness (as shown in squash) due to toxicity, growth habits, or nutrient value, with cascading ecosystem effects...

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When it comes to economics, diversity is key

A study published this week in Nature compared the U.S. economic downturn with a current ecological issue: a decline in biodiversity. In the study, economist Andrew Haldane of the Bank of England and zoologist Robert May of Oxford University basically described the financial system as having similar weaknesses as a monoculture. That is, if all banks are run equally, they are more susceptible to a uniform crisis; much in the way that a pest invasion would have a farther-reaching impact on a plot of land with all of the same species. According to a Scientific American article, “One way to combat this issue is to establish more self-contained “nodes” as has been employed in forest management and even computer networks, so that if one element takes a hit, it doesn’t take down the entire system.” As Sarah Zielinski explained in today’s Surprising Science post, “There are lessons to be had from the world of ecology, say Haldane and May. We could be promoting and managing ecosystem resilience better by requiring banks to have a larger proportion of liquid assets on hand in case of some sort of shock to the system. Taking a lesson from epidemiology, we could focus on limiting the number of ‘super-spreaders’ within the network; but instead of quarantining infected individuals we would somehow limit the number of ‘super-spreader institutions,’ those banks more familiarly labeled as ‘too big to fail.’” Discover’s blog 80beats implied that the current structure could be affected like a trophic cascade: “Modern ecologists recognize that the failure of key species could cause non-linear, cascading ripples that cripple a whole ecosystem.” Some might propose that these comparisons oversimplify the financial system; however, the overall recognition that industry could draw on ecological science to reevaluate such a complex network is a valid argument to make. “Whether or not experts agree that biology is a useful lens through which to study financial markets, Haldane and May suggested that financial regulation is already ‘following in the footsteps of ecology, which has increasingly drawn on a system-wide perspective when promoting and managing ecosystem resilience,’” concluded the Scientific American article. Photo Credit: Dirk...

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