Phylogeny and biogeography of the plant family Calceolariaceae

Abstract

Calceolaria L., Jovellana Ruiz & Pav., and Porodittia G. Don (=Stemotria Wettst. & Harms) toghether constitute the family Calceolariaceae consisting of approximately 300 species distributed manily in South America. The present thesis shows that using morphology as basis for sectional delimitations in the genus Calceolaria is not sufficient to define monophyletic groups. Comparing information from nuclear versus chloroplast sequence data reveal extensive topological discordance, neither of which can easily be related to morphological features. The putative sister relationship between Calceolaria and Jovellana is confirmed, while the phylogenetic position of Porodittia is revealed to be nested deep inside Calceolaria. For Jovellana, a small genus present disjunctly across the Pacific Ocean in South America and New Zealand, a taxonomic revision suggest synonymisation of two previousy recognised species in New Zealand with a larger circumscribed J. sinclairii while the distributional disjunction is revealed as a result of long distance dispersal of recent date. This thesis also explores the presumed close relationship between the origin of the Andes and the evlutionary distriution history of Calceolaria. Biogeographic models for reconstruction of ancestral areas are used to estimate the orgin of the family. By extending the model to simultaneous estiamation of ancestral area in three dimensions based in specimen data a correlation between the uplift history of the Andes and the radiation events of Calceolaria can be established. By optimising morphological traits relating to growth habit and pollination of the genus in a phylogenetic framework, and relating these to the ancestral area reconstruction and the uplift history of the Andes, a suggested radiation pattern for Calceolaria can be established. This pattern follow a south to north trend with an origin in lowland Chile or low Andean slopes, with subsequent radiations to the north correlated with the Altiplano region and the Huancabamba deflection. The pattern also show a correlation between the uplift history of the Andes and the radiation of Calceolaria. This further suggests that the divergence patterns of a group of species cannot be understood without extensive information on not only the phylogeny, but also the prefferred ecological niches and other mechanisms important for radiation success.