RECENT RADIATION OF THE PALMARIACEAE (RHODOPHYTA) 1

• Published in: Journal of Phycology
• Main Authors: Lindstrom, Sandra C., Olsen, Jeanine L., Stam, Wytze T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1996
• Subjects: Pacific; Southern Ocean; North Atlantic
• Online Access: http://dx.doi.org/10.1111/j.0022-3646.1996.00457.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.0022-3646.1996.00457.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.0022-3646.1996.00457.x

ABSTRACT Molecular phylogenetic studies on the evolution of the red algae indicate that this ancient division has many lineages that have recently undergone radiations. One such example is the cold–temperate family Palmariaceae. In this study, sequences from the ribosomal DNA internal transcribed spacer regions were compared among ten species in the Palmariaceae from both Atlantic and Pacific sites, Phylogenetic analyses of sequence data, in which Rhodophysema georgii Batters was used as outgroup and root, indicate a radiation into four clades, three of which contain species of “Palmaria” and the fourth species of Halosaccion. Palmaria palmata (L.) Kuntze, the type and only North Atlantic species in the genus, stands apart from all remaining species in the family and terminates the most basal branch in the rooted tree. The three more derived clades have radiated mainly in the North Pacific. Southern Ocean Palmaria and North Atlantic Devaleraea are hypothesized to have invaded from separate but closely related North Pacific ancestors. The ease with which sequences could be aligned combined with an unsaturated transition: transversion ratio and modest divergence involving predominantly point mutations suggests that the initial radiation is relatively recent (late Miocene–Pliocene) and that the Devaleraea–Palmaria clade is even more recent (late Pliocene–Pleistocene).