Scheme: Wolfson Research Merit Awards
Organisation: Imperial College London
Dates: Aug 2009-Jul 2014
Summary: The project aims at understanding how species originate, especially a highly controversial process called 'sympatric speciation', that is, the evolution of new species without geographic isolation.
First, our work has focused on two species of the palm genus Howea from Lord Howe Island, a minute volcanic island in the Tasman Sea. These palms are now regarded as one of the most compelling examples of sympatric speciation, although this view is still hotly disputed by some authors. Population genetic and ecological data are necessary to provide a more coherent and comprehensive understanding of this emerging model system. Using new genetic data, we were able to confirm that gene flow between these palm species appeared to be extremely limited and restricted to early-generation hybrids. We concluded that these palms originated on Lord Howe Island, that is, speciation was indeed sympatric. We are now in the process to sequence the entire genome of these palms with the aim to identify the genes involved in the make-up of the species.
To evaluate to which extend the Howea palms represent a unique case of speciation, we also surveyed another 113 species of flowering plants endemic to Lord Howe Island. Using genetic and evolutionary data, we were able to demonstrate that about 10% of these species represented new cases of sympatric speciation similar to the palm example. Therefore, speciation without geographic isolation turns out to be much more frequent than previously assumed - turning on its head long-held beliefs about the origin of species diversity.