Document: SCH-3-99-170

Microevolution of physiological traits in natural populations.

SCHMITT, J.* ¹ and M.A.GEBER ²

Brown University, Providence, RI 02912-9127 USA ¹
Cornell University, Ithaca, NY 14853-0001 USA ²

Abstract:
For physiological traits to evolve, they must be genetically variable and they must affect fitness. We will focus on the dual themes of genetic variation and fitness consequences of physiological and developmental traits in natural populations. There is increasing evidence that physiological and developmental traits, such as gas exchange physiology, photomorphogenesis, and development rate, are under selection in the wild. The fitness consequences of these traits are often manifested through intermediate fitness components, such as resource allocation, plant size and flowering time. Their expression and effects are also environment-dependent. There is also evidence that these traits are genetically variable within populations, providing the substrate for natural selection to act on, and differ among populations with different histories of selection. However, response to selection may be constrained by genetic trade-offs among traits and among environments. An exciting prospect for the future is identifying the loci underlying variable phenotypes and detecting selection directly on these loci.

Keywords: genetic variation,fitness consequences

This abstract is being presented at: 2:40 PM in session:
Symposium # 16: Plant Physiological Ecology: Linking the Organism to Scales Above and Below.