PARENT SESSION
Oral Session #65: Evolutionary Ecology/ Population Genetics. Presiding: G. Gerrish.
Thursday, August 9, 2001. 8:00 AM to 12:00 PM. Hall of Ideas J.
Biological invasions as evolutionary processes.
Lee, Carol Eunmi1, 1
ABSTRACT- The fact that many invasive species in freshwater habitats have brackish or saline origins is often overlooked in the literature. These saline immigrants represent some of the most hazardous invaders in fresh water habitats. In this talk, I will review genetic and physiological approaches taken in my laboratory to investigate pathways and mechanisms of biological invasions in aquatic habitats, including studies on zooplankton, zebra mussels, and crayfish. For example, using DNA sequence data, I have reconstructed geographic pathways of freshwater invasion by the estuarine copepod, Eurytemora affinis, from North America, Europe, and Asia. Phylogenetic analysis of populations revealed at least eight independent invasions of fresh water from genetically distinct lineages throughout the world. Physiological experiments showed that the transition to fresh water is not trivial but can occur over multiple generations in some populations. This study provides genetic evidence for rapid transitions to fresh water from saline habitats, repeated invasions on a global scale.
KEY WORDS: phylogeography, biological invasions, ecological genetics, adaptive radiation