HIDDEN DIVERSITY IN MARINE-ALGAE - SOME EXAMPLES OF GENETIC-VARIATIONBELOW THE SPECIES

An important aspect of marine biodiversity studies is identification o f species and subspecies complexes. Here we present a number of exampl es from marine algae in which allozymes, DNA sequences and RAPDs are u sed to identify cryptic species and explore phylogenetic-population le vel relationships over several biogeographic spatial and temporal scal es. In addition to evidence for recent dispersal over large distances, effects of present and past climates are reflected in the phylogeneti c history of many biogeographic complexes. In some cases temperature a daptations can also be detected. Phylogeographic studies on coastal se aweeds and oceanic phytoplankton which utilize molecular genetic data contain a wealth of previously unrecognized information relevant to bi odiversity.