Policies regarding genetically modified organisms (GMOs) need to take biodiversity and regional attributes into account, according to Sandra Mitchell, professor and chair in the Department of History and Philosophy of Science in the Kenneth P. Dietrich School of Arts and Sciences at the University of Pittsburgh Mitchell made her case in a presentation titled "GMOs and Policy in a Complex, Diverse World," delivered during the Global Knowledge Session she coordinated at the American Association for the Advancement of Science's (AAAS) annual meeting in Vancouver, Canada.

"The problem with generating 'global' GMO policies is that policy makers are failing to consider the local variations of a particular region," said Mitchell. "I'm proposing an adaptive policy that's more in tune with the knowledge we've gained about the biodiversity of a specific area."

At the meeting, Mitchell discussed the effects of the bacillus thuringiensis (BT)-a soil-dwelling bacterium commonly used as a biological pesticide-on such different host plants as corn and cotton.

There are nearly 600 strains of BT, each producing a different effect on modified plants, along with the variance of pesticide reduction.

"Reasonable policy needs to take into account such complexities," Mitchell said during her presentation. "The consequences for biodiversity of introducing a GMO are relevant to successful regulation."

Instead of a predict-and-act approach, Mitchell instead suggested multiple, iterated scenario analyses to provide models better attuned to the factual complexity and diversity that GMOs display.

"Policies are also faced with stakeholders who exhibit a range of conflicting values," said Mitchell. "Mediation and management of differences should influence the shape of reasonable policy in the context of value diversity."