3 October 2014
William (Ned) Friedman
Director of the Arnold Arboretum and
Department of Organismic and Evolutionary Biology
Harvard University
Charles Darwin's "abominable mystery" has come to symbolize just about every question we have about the origin and early evolution of flowering plants. What did Darwin think was so abominably mysterious? We will explore this mystery through Darwin's correspondence with some of the most eminent botanists of his time and discover what led Darwin to worry about the early evolutionary history of flowering plants right through the last year of his life. Fossils, insect pollination, and rates of evolutionary change (gradualism vs. punctuationalism) were all part of the complexity of trying to understand where flowering plants came from and how they eventually came to dominate most of Earth's terrestrial ecosystems. Finally, we will look at recent botanical and developmental discoveries associated with the origin and early diversification of flowering plants. Phylogenetic ambiguities, extinction, and basic questions of homology continue to present formidable challenges to solving Darwin's abominable mystery. Nevertheless, our current hypotheses for the earliest phases of flowering plant evolution are radically different from the static, if not dogmatic, views that dominated most of the twentieth century – and a far cry from anything that Darwin might have imagined.