PhD defense: Sam Bruun-Lund

Darwin’s abominable mystery – and evolution and diversification of Ficus L.

Supervisor: Professor & curator Nina Rønsted

Assessment committee
Associate Professor, Docent Thomas Pape (chair)
Associate Professor Anneleen Kool, Natural History Museum, University of Oslo, Norway
Senior Research Professor Mark W. Chase, Royal Botanic Gardens Kew, United Kingdom

Figs (Ficus spp. L.) constitute one of the largest angiosperm lineages with ~800 species distributed in tropical and sub-tropical regions all over the world. Figs may be mostly known for their obligate mutualism with their pollinating fig-wasps (Agaonidae, Chalcidoidea, Hymenoptera). The two linages have codiversified for the last 75 million years. Additionally, figs present a diversity of habits and habitat usage and are considered keystone species in rainforests due to abundant fruit set. Our understanding of the evolutionary history of figs is based on the milestone monographs of Corner and Berg, primarily based on morphology. Meanwhile, the advent of DNA sequencing has unravelled conflicting relationships and questioned all our understanding of the evolution and diversification of figs. However, decades of Sanger sequencing have not provided a comprehensive phylogenetic hypothesis needed to re-test standing hypotheses about the origin and specificity of the mutualism, nor why the figs have been successful in adapting to many environments. In this PhD project, the figs have entered the era of high-throughput sequencing (HTS) with investigations of how their diversification patterns may explain why there are so many species.