ALEXANDRA VAN DER GEER

During the Plio-Pleistocene many islands of the World were inhabited by endemic mammals of mainland origin. Today, most of these island endemics are extinct and are known to us only by their fossil remains. The insular mammals present unique adaptations to the island environment compared to their mainland relatives, such as smaller size and robust and short limbs. I participate in the project Of Mice and Mammoths of Mark Lomolino, Dov Sax and Maria Rita Palombo by investigating the importance, degree and direction of body size changes in insular mammals.

One of the aims of the project was to test the generality of the so-called island rule. The database assembled thus far comprises 1593 populations of insular mammals (439 species, including 63 species of fossil mammals).We found that the body size index (body mass of the insular population relative to the mainland population) was significantly and negatively related to the mass of the ancestral or mainland population across all mammals and within all orders of extant mammals analysed, and across palaeo-insular (considered separately) mammals as well. Insular body size was significantly smaller for bats and insectivores than for the other orders studied, but significantly larger for mammals that utilized aquatic prey than for those restricted to terrestrial prey. Our main conclusions are that the island rule appears to be a pervasive pattern, exhibited by mammals from a broad range of orders, functional groups and time periods. There remains, however, much scatter about the general trend; this residual variation may be highly informative as it appears consistent with differences among species, islands and environmental characteristics hypothesized to influence body size evolution in general. The more pronounced gigantism and dwarfism of palaeo-insular mammals, in particular, is consistent with a hypothesis that emphasizes the importance of ecological interactions (time in isolation from mammalian predators and competitors was between a hundred thousand to a million years for palaeo-insular mammals, but less than ten thousand year for most extant populations of insular mammals. While ecological displacement may be a major force driving diversification in body size in high-diversity biotas, ecological release in species-poor biotas often results in the convergence of insular mammals on the size of intermediate but absent species.

The project ISOLARIO investigates the impact of natural and anthropogenic changes to the insular environments and the importance of those changes to human culture. It is a multidisciplinary project, drawing on the expertise of an international team of scientists from different fields: Geosciences, Life Sciences and Humanities. The project is entitled Island biodiversity and cultural evolution: examples from the Eastern Mediterranean, Madagascar, Mauritius and Philippines during the past 800,000 years (in short ISOLARIO). ISOLARIO (MIS 375910, KA:70/3/11669) is funded by the European Union (ESF) and Greek national funds through the Operational Program Education and Lifelong Learning of the National Strategic Reference Framework (NSRF)-Research Funding Program THALIS-UOA. Duration 3 years. Coordinator: Hara Drinia. In collaboration with institutes in Germany, Greece, Spain, the Netherlands and the USA.
In order to carry out the project, we selected islands from three different areas: the Eastern Mediterranean Sea (Crete, Karpathos and Cyprus), the Indian Ocean (Madagascar and Mauritius) and the western Pacific Ocean (Philippines: Luzon and Masbate). These areas have a different geologic, biogeographic and ethnographic background. Furthermore, these islands were colonized by humans during different periods in history (ranging from 800,000 years ago till the 17th century.)

During 2008 and 2009 I was full-time working on a reference handbook on extinct island faunas with own funding. The result was published as Evolution of Island Mammals: Adaptation and Extinction of Placental Mammals on Islands by Wiley-Blackwell, Oxford, UK. My co-authors are John de Vos, George Lyras and Michael Dermitzakis. The various Chapters were reviewed by specialists in the field. For more info, click here. The book is dedicated to the memory of Paul Yves Sondaar (1934-2003), the founder of paleo-island studies in the Netherlands and in Greece.





Evolution of a hypothetical island fauna. Drawing George Lyras

In 2008 I participated in a project to improve the visibility of the Museum on the web. I wrote the content pages (in English) for the website, designed the general lay-out, selected appropriate images and translated the collection database records into English and French. Visit the new homepage of the Museum. I also participated in the development of an educational DVD for the Museum for children.
Another digitalization project (2007) concerned the collection of the Natural History Collection at Vrissa, Lesvos (Greece), part of the Museum of Palaeontology and Geology of the National and Kapodistrian University of Athens. This project consisted of two parts: one, creating a database with relevant information and a digital image of all specimens of the collection and two, the design and development of a web portal. Fossils form the major part of the Vrissa collection. Minor parts are the minerals and rocks, the plants and the taxidermy specimens of birds and mammals. I was involved in both parts of the project. For the database, I organized the data, specified the required fields and translated the data into xml. For the website, I wrote the texts for the palaeontological section, including descriptions of the extinct animals and their evolution, both popular as well as scientific. Below are some examples from the database.

Partly with funding from the National and Kapodistrian University of Athens (Museum of Paleontology and Geology), I wrote several shorter and longer texts on various paleontological subjects, e.g. Paradolichopithecus (a Plio-Pleistocene papionin), Candiacervus (a Pleistocene deer), and island faunas, apart from teaching activities (2005 and 2006). I also actively participated in the Museum's summer fieldwork, e.g. on Lesvos and Crete.




F-site of Vatera (Lesvos, Greece)

Gerani 1-4 (Crete, Greece)

Katharo Plain (Crete, Greece)

Mitsouna (Naxos, Greece)