Ancient lineages with recent histories: insights into the evolution of ferns and cycads
25 May 2012
Dr Nathalie Nagalingum (Royal Botanic Garden Sydney) hosted by Murray Henwood The ferns and cycads have ancient fossil records, and cycads in particular have captured wide interest as survivors and relicts from the age of dinosaurs. However, fossil-calibrated molecular phylogenies demonstrate that living cycad species are not at all ancient. Instead they diversified recently, only ~12 million years ago and ~55 million yearsafter the extinction of the dinosaurs. The parallel radiations within multiple genera are nearly synchronous and are global. Just as remarkably, they ceased to diversify. These findings indicatethat cycads likely responded to a change in global climate occurring 12 million years ago. Despite their antiquity, ferns are the second-most diverse plantgroup after flowering plants. Using an Australia-wide dataset for ferns, a phylogeny is used to understand current diversity and patterns of endemism.
Location: DT Anderson Lecture Theatre, A08