Many plant taxa that occur on the Eastern Arc Mountains have complex present day distributions that pose many questions about their geographical and evolutionary origins.  For example, species that occur on the ancient crystalline Eastern Arc Mountains may also have populations on the comparatively recent nearby volcanic mountains such as Meru and Kilimanjaro.  Given that these relatively young mountains are not linked to the Eastern Arc by forest, when have Eastern Arc species colonised them and from where? 

When we look at distributional patterns within species, the relationship between their populations is not always clear, and their relative ages are usually unknown.  Although we can formulate hypotheses about their evolutionary origins based on their current geographical distribution, these hypotheses are rarely testable based on morphological characters.  Characterising the phylogenetic relationships between populations of key taxa of the Eastern Arc flora using DNA sequence data, and comparing phylogenetic relationships with the species’ distributional patterns will inform on evolutionary and colonisation histories.  Comparison of these phylogeographical patterns for multiple species will enable us to identify fundamental biogeographical patterns within the region. 

Additional work using molecular markers will look at taxa where ongoing speciation is suspected.  Some species with a relatively broad altitudinal range in the Eastern Arc and neighbouring lowland Coastal Forests are subdivided into isolated and morphologically distinct varieties.  Do these varieties indicate substantial ecological and morphological plasticity within a species, or are they an example of speciation in progress?  Investigating the ancient and recent evolutionary relationships across the Eastern Arc will increase our understanding of how the incredible biodiversity of this region has been generated, complimenting the palaeoecology, biogeography and modelling components of the project.