Symposium #6: Ecological Consequences of Adaptive Evolution Among Invasive Species in Terrestrial and Marine Systems.

Organized by: E. Grosholz and J. Maron.
Sponsored by: Long Term Studies Section.
Sunday, August 6, 2000
1:00 PM to 5:00 PM
Ballroom III - Cliff Lodge

Ecosystems throughout the world are being threatened by the invasion of introduced species. What permits certain introduced species to disrupt the systems into which they are introduced remains widely debated. Evidence is now accumulating that organisms placed in new environments can evolve rapidly, and that the resulting changes in phenotypic characters such as size, prey preferences or host usage can influence the strength of ecological interactions. For example, organisms can be larger in their introduced versus native range; increased stature often may enhance competitive ability and therefore the likelihood of spread.

The goal of this symposium is to present some of the exciting recent evidence that suggests that introduced organisms have altered phenotypes compared to native conspecifics. Speakers will evaluate whether changes in phenotype result from plasticity, founder effects, or from rapid evolution, and explore how altered phenotype may influence ecological interactions and invasibility. While ecological hypotheses for what makes organisms successful invaders are manifold, the importance of plasticity or evolutionary change in altering phenotypic characters that can facilitate invasion is often ignored. The objective of this symposium is therefore to provide a synthesis of both ecological and evolutionary hypotheses relating to invasion. The proposed symposium will bring together scientists who work on both plants and animals in marine and terrestrial systems. The broad representation of organisms and habitats will appeal to a broad range meeting attendees. In addition, the issues covered in this symposium ranging from predator-prey dynamics, and host plant-insect interactions to phenotypic evolution, will be of general broad interest to many in the society. This kind of approach, one that tackles an important problem in applied ecology by combining basic ecological and evolutionary approaches in very different systems, has been poorly represented by past symposia and contributed paper sessions.