FREDERICQ, SUZANNE AND JUAN M. LOPEZ-BAUTISTA.* Department of Biology, University of Louisiana at Lafayette, Lafayette, LA 70504-2451. - Phylogeny, biogeography and life history evolution in the red algal family Phyllophoraceae (Gigartinales).
Red algae are exceptional for the great diversity in reproductive
morphology and for their complex life histories. In particular, the
family Phyllophoraceae, consisting of ~100 species worldwide, stands
out in exhibiting a wide spectrum of unique life history types that
makes it unusually interesting for assessing the phylogenetic
importance of reproductive traits relative to classification criteria.
Type of life history and position of the reproductive structures on
the plant body have traditionally formed the basis for separating
eleven genera in the Phyllophoraceae; however, phylogenetic analyses
inferred from three sets of DNA sequences [chloroplast-encoded rbcL,
nuclear large-subunit ribosomal RNA gene (LSU), and internal
transcribed spacer regions (ITS) of nuclear ribosomal DNA], instead
indicate a lack of correlation between type of life history and
phylogenetic relationships among the established taxa. This lack of
correlation dramatically challenges all of the traditional taxonomy.
The study will answer the question which morphological features and
which aspects of life history evolution can be used as meaningful
indicators of phylogenetic relationships in the Phyllophoraceae. The
results will also be addressed in light of global biogeographic
hypotheses for the family. (Supported by NSF DEB-9903900 and LA
Key words: algae, biogeography, life history, morphology, phylogeny, Rhodophyta