Representation of a dissimilarity matrix using reticulograms
Pierre Legendre1 and Vladimir Makarenkov2
1 Département de sciences biologiques, Université de Montréal,
C.P. 6128, succursale Centre-ville, Montréal (Québec), Canada H3C 3J7
E-mail:
Web site: http://www.fas.umontreal.ca/biol/legendre/
2 Département d’informatique, Université du Québec à Montréal,
C.P. 8888, succursale Centre-Ville, Montréal (Québec), Canada H3C 3P8
E-mail:
Abstract. A reticulogram is a general network capable of representing a reticulate evolutionary structure. It is particularly useful to portray relationships among organisms that may be related in a non-unique way to their common ancestor; a structure of this kind cannot be represented by a dendrogram or a phylogenetic tree. We are proposing a new method for construction of reticulograms representing a given distance matrix. Reticulate evolution applies first to phylogenetic problems; it has been found in nature, for example, in the within-species micro-evolution of eukaryotes and in lateral gene transfer in bacteria. In this talk, we are proposing a new method for reconstructing reticulation networks and developing applications of the reticulate evolution model to ecological biogeographic, population micro-evolutionary, and hybridization problems. The first example considers a spatially-constrained reticulogram representing the postglacial dispersal of freshwater fishes in the Québec Peninsula; the reticulogram provides a better model of postglacial dispersal than a (bi)furcating tree model. The second example depicts the morphological similarities among local populations of muskrats in a river valley in Belgium; adding supplementary branches to a tree depicting the river network leads to a better representation of the morphological distances among local populations of muskrats than a (bi)furcating tree structure. A third example involves hybrids between plants of the genus Aphelandra.
References
Legendre, P. (Guest Editor) 2000. Special section on reticulate evolution. Journal of Classification 17: 153-195.
Legendre, P. and V. Makarenkov. 2002. Reconstruction of biogeographic and evolutionary networks using reticulograms. Systematic Biology 51: 199-216.
Makarenkov, V., P. Legendre & Y. Desdevises. 2004. Modelling phylogenetic relationships using reticulated networks. Zoologica Scripta 33: 89-96.
Makarenkov, V. & P. Legendre. 2004. From a phylogenetic tree to a reticulated network. Journal of Computational Biology 11: 195-212.