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Fluctuating asymmetry (FA) is the terminology used to describe small variations from perfect symmetry in otherwise bilaterally-symmetrical characters in an organism (Moller and Swaddle, 1997). It is believed to arise in consequence of developmental instability experienced during ontogeny that is caused by various stresses, including both genetic and environmental factors (Martel et al., 1999; Cornelissen and Stiling, 2005); and it has been studied extensively in animals but less so in plants (Moller and Shykoff, 1999).
In the first study to address the effects of atmospheric CO2 enrichment on leaf asymmetry and how herbivores respond to these effects, Cornelissen et al. (2004)1 opened up a whole new window through which to view the world of the future in terms of the potential effects of the ongoing rise in the air’s CO2 content on the plant and animal components of the biosphere. The Cornelissen et al. study was conducted on a native scrub-oak community at the Kennedy Space Center, Titusville, Florida, USA, which is dominated by myrtle oak (Quercus myrtifolia) and sand live oak (Quercus geminata) under atmospheric CO2 concentrations of approximately 370 and 700 ppm.