An evolutionary tree is a rooted tree where each internal vertex has at least two children and where the leaves are labeled with distinct symbols representing species. Evolutionary trees are useful for modeling the evolutionary history of species. An agreement subtree of two evolutionary trees is an evolutionary tree which is also a topological subtree of the two given trees. We give an algorit...

The paper proposes a model for measuring and valuing biodiversity based on evolutionary information, called the phylogenetic tree model. While avoiding the strong restrictions of Weitzman’s [Quart. J. Econ. 107 (1992) 363] “cladistic” approach, the phylogenetic tree model retains much of the mathematical simplicity of the cladistic model. In particular, in the phylogenetic tree model the divers...

We describe a visualization tool which allows a biologist to explore a large set of hypothetical evolutionary trees. Interacting with such a dataset allows the biologist to identify distinct hypotheses about how different species or organisms evolved, which would not have been clear from traditional analyses. Our system integrates a point-set visualization of the distribution of hypothetical tr...

16 Introduction 17 Materials and Methods 19 Results 22 Discussion 27 Acknowledgements 32 Annexure 1 33 3 Seasonal fluctuations of epilithic diatoms and extracellular polymeric substances from the littoral zone of Lake Constance 40 Abstract 4

The comparative analysis of phylogenies obtained using different phylogenetic methods or different gene sequences for a given set of species, is usually done by computing some quantitative measure of similarity between the phylogenetic trees. Such a quantitative approach provides little insight into the actual similarities and differences between the alternative phylogenies. In this paper, we p...

Previous work has shown the perhaps surprising result that, for any binary phylogenetic tree T , there is a set of four characters that define T . Here we deal with the general case, where T is an arbitrary X-tree. We show that if d is the maximum degree of any vertex in T , then the minimum number of characters that identify T is log2 d (up to a small multiplicative constant).