Exploring phylogenetic aspects of radiations of derived ferns: using the epiphytic polygrammoid as a model lineage

• Applicant: Professor Dr. Harald Schneider
• Subject Area: Evolution and Systematics of Plants and Fungi
• Term: from 2004 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5424235

The objective of the project is to provide insights in the phylogenetic structure of diversification events. Several independent radiations will be studied but these are connected in a phylogenetic framework. This approach will generate new data about proposed correlations between factors such as substitution rates, speciation rate, and key innovation. Polygrammoid ferns are chosen as a model system based (1) on the well-established global phylogeny of the group providing a phylogenetic framework, (2) the conserved ecological preference (epiphytism), and (3) preliminary results that indicate correlations between substitution rate and/or speciation rate and/or key innovations in eight selected diversification events. The phylogeny of each radiation will be reconstructed using nucleotide sequences of cpDNA regions and nuclear genes with and without including morphological characters. Taxon sampling will cover substantial part of the diversity of these clades. Substitution rates and speciation rates will be calculated for each diversification event and tests will be performed to explore correlations between these two rates and the influence of key innovations such as humus collectors, ant-fern interaction, improved desiccation tolerance, and green spores. Theoretical aspects will be explored using models of diversification events that are compared with the generated empirical data.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1127: Radiations - Origins of Biological Diversity