Evolution and ultraviolet light tolerance in algae

Ultraviolet light (UV) kills. This is a well-established fact and the basis for current concern that ozone depletion is a serious threat to the biosphere. However, species have variable tolerances to UV exposure, and knowing that UV is lethal does not provide enough information to explain how ecosystems function under ambient and changing ultraviolet regimes. Three papers in this issue of the Journal of Phycology deal with the UV photobiology of algae (Dillion and Castenholz 1999, Franklin et al. 1999, Underwood et al. 1999). These studies build on previous work and are representative of an important trend in ecological UV research over the past decade: phycologists are moving well beyond merely documenting the inhibitory and lethal aspects of UV and are focusing more directly on understanding the biological, ecological, and evolutionary bases for UV tolerance.