Meeting Abstract
As environments across the globe change at unprecedented rates, organisms must cope with these changes. The primary evolutionary mechanisms for coping with environmental changes include phenotypic plasticity and selection. Plasticity can be used as a short-term solution to immediate change, and selection primarily a long-term solution that allows populations to cope with environmental change over generations. However, the success of these mechanisms are dependent upon the available variations of phenotypes that can be produced. Phenotypes that are available to plasticity or selection are affected by factors that produce phenotypic variation. One such factor is stress, which is thought to increase under novel conditions. An example of a phenotype whose variation is thought to be affected by stress is bilateral symmetry. In bilaterally symmetrical organisms, there is some background level of fluctuating asymmetry (FA); the random deviation from typically expected symmetrical development under given environmental conditions. Under stressful conditions, increases in FA result from developmental instability (DI) and thus there is an increase in phenotypic variation in these typically symmetrical traits. One important factor in ecosystem changes is the introduction of novel predators. In this study we will examine how the introduction of northern pike (Esox Lucius), and the increased stress it is thought to cause, will morphologically affect the threespine stickleback (Gasterosteus aculeatus) population in Scout Lake, Alaska. Using preserved samples of stickleback from 1998-2000 (pre-pike) and 2001-2009 (subsequent to pike establishment), we will examine this prey population’s morphology for fluctuating asymmetry (FA). We predict that FA in this threespine stickleback population will increase subsequent to pike introduction.
