General Research Interests

A more specific interest is the historical biogeography of the Indo-Pacific area. This area is well suited for this kind of research for several reasons. Firstly, it is a place where three of the earth's plates interact, and is therefore also widely studied by geologists. Secondly, the land masses consist mostly of islands, making the recognition of areas of endemism relatively easy. And thirdly, it is inhabited by a large number of monophyletic groups with many species of restricted distribution. Moreover, its flora and fauna are actively investigated by many taxonomists from The Netherlands and abroad for the Flora Malesiana and Fauna Malesiana projects, coordinated by the National Herbarium Netherlands, Leiden branch, and the National Natural History Museum, respectively. Together with Drs. P. Hovenkamp and P.C. van Welzen, an analysis of the biogeographic history of this region using a large database was presented at the XVI International Botanical Congress.

In addition to the above, I am interested in the phylogeny of Anacardiaceae. At the Bolus Herbarium, University of Cape Town, I started work on a cladistic and biogeographic analysis of the genus Ozoroa Del. (Anacardiaceae), and the related monotypic genus Heeria (Thunb.) Meissn. Ozoroa contains about 40 species, and occurs on the savannas and shrublands of sub-Saharan Africa. Two subregions have particularly high numbers of endemics: SE Congo-Malawi-Zambia, and S Namibia-N South Africa. In the mountain areas of the Western Cape (South Africa) it is replaced by Heeria. This pattern of a Cape endemic with its closest relatives in tropical Africa is quite unusual, and is the main reason for doing this investigation.

The period January-April 2000 I spent at New York Botanical Garden's Lewis B. and Dorothy Cullman Program for Molecular Systematics Studies doing molecular phylogenetic research on the tribe Rhoeae, in cooperation with Drs. L. Struwe and J. Mitchell.

During 2001-2002 I was a post-doc at the Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, to construct a phylogeny of the genus Yponomeuta (Lepidoptera: Yponomeutidae) using primarily molecular data (16S, ITS, and COII). Trees are constructed using maximum parsimony, maximum likelihood and Bayesian inference methods on the different data partitions separately, and in a total-evidence approach. Thy resulting taxon trees are used to reconstruct the evolutionary events that have led to the present distribution of the genus, both geographically and in terms of the host plants used. This work, done in cooperation with Prof.Dr. Steph Menken, his PhD student Niek Lieshout, and Dr. Sandrine Ulenberg, has been published in PLoS ONE.

At present I am honorary scientist at the NCB Naturalis, herbarium branch in Leiden. My main interest at the moment is once more the biogeography of Southeast Asia, which I analyse using an expanded version of my 1999 data matrix, and the step matrix approach I am developing further. The next step will be inclusion of the age of vicariance events.

According to Web-Counter connections have been made

to this page since February 16, 2010

Last update: May 24, 2010.

WWW home pages are publicly accessible. Reproduction of the published material, however, is restricted to personal use only. For all other purposes the permission of the author is required.