Bibliographic Detail
Skaloud, P., Nemjová, K., Veselá, J., Cerná K. & Neustupa, J., 2011
Reference:
Skaloud, P., Nemjová, K., Veselá, J., Cerná K. & Neustupa, J. (2011). A multilocus phylogeny of the desmid genus Micrasterias (Streptophyta): evidence for the accelerated rate of morphological evolution in protists. Molecular Phylogenetics and Evolution 61: 933-943.
Publication Date:
"Available online 3 September 2011"
Abstract:
Micrasterias, the name of which is derived from the Greek for little star, comprises possibly the most
spectacularly shaped desmids (Desmidiales, Streptophyta). Presently, the genus Micrasterias includes
about 60 traditional species, the majority of which were described in the early 19th century. We used
a comprehensive multigene dataset (including SSU rDNA, psaA, and coxIII loci) of 34 Micrasterias taxa
to assess the relationships between individual morphological species. The resulting phylogeny was used
to assess the patterns characterizing the morphological evolution of this genus. The phylogenetic analysis
led to the recognition of eight well-resolved lineages that could be characterized by selected morphological features. Apart from the members of Micrasterias, three species belonged to different traditional desmid genera (Cosmarium, Staurodesmus, and Triploceras) and were inferred to be nested within the genus.
Morphological comparisons of these species with their relatives revealed an accelerated rate of morphological evolution. Mapping morphological diversication of the genus on the phylogenetic tree revealed
profound differences in the phylogenetic signal of selected phenotypic features. Whereas the branching
pattern of the cells clearly correlated with the phylogeny, cell complexity possibly reected rather their
adaptive morphological responses to environmental conditions. Finally, ancestral reconstruction of distribution patterns indicated potential origin of the genus in North America, with additional speciation
events occurring in the Indo-Malaysian region.
